Dissertations / Theses: 'Esters – Synthesis'

1

Scott, Richard. "Synthetic approaches towards the synthesis of phorbol esters." Thesis, University of Reading, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.314251.

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Belogi, Gianluca. "Boronate esters in oligosaccharide synthesis." Thesis, University of Birmingham, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.367628.

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3

Zheng, Xueyan. "Regioselective Synthesis of Cellulose Esters." Diss., Virginia Tech, 2014. http://hdl.handle.net/10919/49540.

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Cellulose is an extraordinarily abundant polymer that can be harvested and purified from trees and other renewable sources. Cellulose derivatives have been widely used as coatings, optical films, fibers, molded objects, and matrices for controlled release. The properties of cellulose derivatives are not only affected by the degree of substitution, but also by the position of substitution. In order to establish the structure-property relationships of cellulose derivatives, it is of great importance to impart regioselectivity into functionalized cellulose. However, regioselective substitution of cellulose is extremely challenging, especially in the synthesis of regioselectively functionalized cellulose esters due to the unstable ester bond under aqueous alkaline or acid conditions. In this dissertation, the main objective is to search for new tools to synthesize regioselectively substituted cellulose esters, to understand how structural changes impact properties and performance, and thus to design cellulose derivatives delivering high performance. Several strategies for regioselective preparation of cellulose esters are discussed in detail. The obtained regioselective cellulose esters were fully characterized analytically.
Ph. D.

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4

Schaff, Jilla. "Fluorinated esters : synthesis and identification." PDXScholar, 1988. https://pdxscholar.library.pdx.edu/open_access_etds/3921.

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Reactions of different alcohols with 2-hydroxy - 1- trifluoromethyl -1,2,2-trifluoroethanesulfonic acid sultone were studied. Six new esters were prepared: C6F5OC(O)CF(CF3)SO2F, CH3CH2OC(O)CF(CF3)SO2F, CF3CH2OC(O)CF(CF3)SO2F, (CF3)2CHOC(O)CF(CF3)SO2F, CH2=CHCH20C(O)CF(CF3)SO2F, (CH2OC(O)CF(CF3)SO2F)2. Analytical data, infrared, nmr and mass spectra are presented supporting the proposed structures for these new compounds.

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5

Mohammadi, Farahnaz. "Total synthesis of lavendamycin esters and analogs." Virtual Press, 1993. http://liblink.bsu.edu/uhtbin/catkey/865964.

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The purpose of this research was to synthesize 7-bromodeaminolavendamycin methyl ester (11), deaminolavendamycin methyl ester (19), 7-N-isobutyryldemethyllavendamycin methyl ester (54), 7-N-acetyldemethyllavendamycin ethyl ester (64), 7-Nisobutyryldemethyllavendamycin butyl ester (76), 7-N-isobutyryldemethyllavendamycin tbutyl ester (78), 7-N-cetyldemethyllavendamycin phenyl ester(79), and 7-Nisobutyryldemethyllavendamycin isopropyl ester (80).Lavendamycins 54, 64, 76, 80 were synthesized via the Pictet-Spengler condensation of the corresponding tryptophan esters with 7-N-acetamido-2-formylquinolinedione (91) or 7-N-isobutyramido-2-formylquinolinedione (92). 3-Carbomethoxy-l-( 8-hydroxyquinoline2-yl )-4-methyl-(3-carboline (18), and 3-carbomethoxy-l-(5-acetamido-8-acetoxy-7bromo-2-yl)-4-methyl-(3-carboline (109) were also prepared through the Pictet-Spengler condensation of p-methyl tryptophan methyl ester with 2-formyl-8-hydroxyquinoline (103) and 5-acetamido-8-acetoxy-7-bromo-2-formylquinoline (108), respectively.Compounds 18 and 109 were oxidized by potassium dichromate or Fremy's salt to give deaminolavendamycin methyl ester (19) and 7-bromodeaminolavendamycin methyl ester (11) respectively.7-Isobutyramido-2-formylquinoline-5,8-dione (92) was prepared according to the following general procedure. 8-Hydroxy-2-methylquinoline (26) was reacted with a 70% mixture of HNO3 / H2SO4 to produce 8-hydroxy-2-methyl-5,7-dinitroquinoline (39). Compound 39 was reduced by H2 / Pd-C and then reacted with isobutyric anhydride in the presence of sodium sulfite and sodium acetate to produce 88. Recrystallization of 88 with methanol gave 5,7-diisobutyramido-8-hydroxy-2-methylquinoline (98). Compound 98 was suspended in acetic acid and oxidized by a solution of potassium dichromate to give 7isobutyramido-2-methylquinoline-5,8-dione (90). The dione derivative 90 was oxidized by selenium dioxide in 1,4-dioxane to yield the target aldehyde 92. 2-Formyl-8hydroxyquinoline (103) was synthesized through a selenium dioxide oxidation of 8hydroxy-2-methylquinoline (26).Ester 96 was prepared by the Fischer esterification of L-tryptophan with an excess amount of isopropyl alcohol in the presence of dry HCI. L-Tryptophan phenyl ester (97) was prepared through a two-step reaction. NCBZ-L-tryptophan (101) was treated with phenol and BOP reagent in the presence of triethylamine in acetonitrile to yield NCBZ-L tryptophan phenyl ester (102). The N-protected ester was reduced to L-tryptophan phenyl ester (97) by ammonium formate in the presence of palladium on charcoal in N,Ndimethylformamide. Esters 93-95 were obtained by the treatment of their commercially available hydrochloride salts with 14% NH4OH and then extraction with ethyl acetate.The structures of the compounds 11, 18, 19, 54, 64, 76, 80, 88, 90, 92, 96, 97, 98, 102, 103, 106, 108 and 109 were comfirmed through tH NMR, IR, and MS. Elemental analyses of 90, 92, 96, 98, 103 and 106 and HRMS of 98, 19, 54, 76, 95, 109 are also included. 1H NMR are also provided for compounds 39, 94,95.
Department of Chemistry

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6

Smyth, G. Darren. "Asymmetric synthesis via #beta#-amino esters." Thesis, University of Oxford, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.297678.

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7

Khan, Ghulam Ahmed. "Enzymatic synthesis of L-DOPA esters." Thesis, University of Reading, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.333598.

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8

Olang, Fatemeh. "Total synthesis of lavendamycin analogs." Virtual Press, 1995. http://liblink.bsu.edu/uhtbin/catkey/958797.

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The synthesis of 7-N -furoyllavendamycin methyl ester (35), 7-N -furoyl demethyllavendamycin methyl ester (36), 7-N -furoyldemethyllavendamycin ethyl ester (37), 7-N -furoyldemethyllavendamycin propyl ester (38), 7-N -furoyl demethyl lavendamycin butyl ester (39), 7-N -furoyldemethyllavendamycin isoamyl ester (40),7-N -furoyldemethyllavendamycin cyclohexyl ester (41), 7-N -furoyldemethyl lavendamycin octyl ester (42), 7-N -furoyldecarboxydemethyllavendamycin (43), and demethyl lavendamycin isoamyl ester (44) are described. Pictet-Spengler condensation of 7-furoylamino-2-formylquinoline-5, 8-dione (55) with (3-methyltryptophan methyl ester (4), Ltryptophan methyl ester (56), L-tryptophan ethyl ester (57), L-tryptophan propyl ester (58), L-tryptophan butyl ester (59), L-tryptophan isoamyl ester (60), L-tryptophan cyclohexyl ester (61), L-tryptophan octyl ester (62), L-tryptamine (63), in xylene, or anisole afforded ten lavendamycin analogs.Aldehyde 55 was prepared according to the following general procedure.Nitration of 8-hydroxy-2-methylquinoline (30) gave 8-hydroxy-2-methyl-5,7dinitroquinoline (31). Compound 31 was then hydrogenated and acylated with 2-furoyl chloride (or acetic anhydride ) to yield 5,7-difuroylamino-8-hydroxy-2-methylquinoline (53) or 5,7-diacetamino-8-acetoxy-2-methyl- quinoline (33). Compounds 53 and 33 were oxidized by potassium dichromate to give the corresponding 5,8-diones 54, and 27. Treatment of 53, and 27 with selenium dioxide in refluxing wet dioxane afforded compounds 55 and 28.Compound 4 was previously prepared by other members of our group, compounds 56, 57, 59, and 62 were obtained through the neutralization of the corresponding Ltryptophan ester hydrochlorides with a 14% ammonium hydroxide solution followed by extraction. Compounds 58, 60, 61 were synthesized via a Fischer esterification of Ltryptophan with : propyl alcohol, isoamyl alcohol, and cyclohexyl alcohol saturated with hydrogen chloride.The structures of compounds 53, 54, 55, 35, 36, 37, 38, 39, 40, 41, 42, 43, and 44 were confirmed through 1H NMR, IR, EIMS, and HRMS. Elemental analyses of 53, 54, and 55 are also included.The structures of esters 56, 57, 58, 59, 60, 61, 62, and 63 were confirmed by 1H NMR.
Department of Chemistry

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9

Garrais, S. "Synthesis of Lipid Structures and Matricaria Esters." Thesis, Queen's University Belfast, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.517311.

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Tajuddin, Hazmi. "New strategies for synthesis with boronate esters." Thesis, Durham University, 2013. http://etheses.dur.ac.uk/6986/.

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Aryl and alkyl boronic acids and their derivatives have a broad variety of applications, ranging from uses in medicines to cross-coupling partners in modern organic synthesis. This thesis presents the work undertaken in both the synthetic and application aspects of this important class of synthetic intermediates. Chapter 1 gives a brief overview on the bonding and physical properties of boronic acids, their synthesis and applications. Chapter 2 shows that the activation of C-H bonds in the iridium-catalysed borylation of arenes is contingent on C-H acidity in the absence of steric effects, allowing for the prediction of regiochemistry through a simple 1H NMR analysis of the starting material. Chapter 3 shows that the high electronic barrier hindering the borylation of C-H bonds alpha to a pyridyl nitrogen can be overcome through steric effects, and that the resultant α-pyridyl boronate can be used, in-situ, in Suzuki-Miyaura cross-coupling reactions. Chapter 4 describes the development of C-H borylation/1,4-conjugate addition sequence, for the synthesis of β-aryl ketones and the corresponding alcohols under reducing conditions. Chapter 5 describes the development of a new methodology for the preparation of alkyl boronate esters through copper-catalysed borylation of alkyl halides.

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11

Jing, Stanley Mofor. "Synthesis of Resveratrol Esters and Aliphatic Acids." Digital Commons @ East Tennessee State University, 2011. https://dc.etsu.edu/etd/1382.

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Resveratrol (RV) is a naturally occurring phytoalexin of the stilbenoid family produced by some plant species, and present in grape skin, peanuts, and red wine. It has been found to exhibit anti-cancer, anti-inflammatory, anti-viral, anti-aging, cardio protective, and anti-oxidant properties. Bioavailability is a huge setback that limits the potentials of RV. As a result, efforts have been made to design and synthesize RV esters and aliphatic acids in an attempt to increase its bioavailability, solubility in water, and possibly improving its biological activities. Resveratrol esters, 3,5,4'-triacetyloxystilbene (2) and Methyl 1,1',1''- (3,4',5-stilbenyl)-1,6-hexanedioate (3) have been synthesized. Compound 3 is a new compound, synthetic yield is 88%, and purity is above 95% based on NMR integration. Both 2 and 3 are good candidates for biological evaluation. 3 was used as a precursor in the synthesis of resveratrol aliphatic acid, 8-(3',5'-dihydroxylstilbene-4''-oxy)-3,6-dioxocotanoic acid (9). First, 2 was hydrolyzed to resveratrol diester, 3,5-diacetyloxystilbene (4). Mitsunobu reaction of 4 and methyl 8-hydroxy-3,6-dioxooctanoate (7) was then carried out to afford methyl 8-(3',5'-diacetyoxystilben-4''-oxy)-3.6-dioxooctanoate (/5), which was then hydrolyzed to afford 9 in total 43.6 % yield. Structures of all newly synthesized compounds were confirmed by 1H and 13C NMR spectroscopy.

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12

Evans, Melanie Daryl. "Asymmetric induction in reactions of chiral carboxylic esters and silyl enol ethers." Thesis, Rhodes University, 1998. http://hdl.handle.net/10962/d1006762.

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Several camphor and pinane derivatives have been synthesised and evaluated for use as chiral auxiliaries in asymmetric synthesis. Various blocking groups have been attached to the camphor skeleton in attempts to improve stereofacial selectivity; these include α-methoxybenzyl and xylyl groups, and novel stereoisomeric ketal moieties derived from meso- and (R,R)-(-)-2,3-butanediol. Benzylation reactions carried out on the lithium enolates of ester derivatives of the camphor-derived chiral auxiliaries afforded α-benzylated products in 5-60% diastereomeric excess. Stereochemical aspects have been explored using high resolution NMR, X-ray crystallographic and computer modelling techniques, and hydrolysis of selected α-benzylated products has permitted the diasteroselective bias to be confirmed. Opposite configurations at the new stereogenic centre are clearly favoured by the xylyl and ketal blocking groups - an observation rationalised in terms of the presence or absence of chelating potential in the blocking group. Baylis-Hillman reactions carried out on a series of specially prepared camphor-derived acrylic esters containing the ketal blocking group exhibited both low diastereoselectivities (0-30% d.e.) and very long reaction times. Chiral silyl enol ethers, synthesised using both pinane and camphor derivatives as chiral auxiliaries, showed up to 20% diastereomeric excess in MCPBA oxidation, alkylation and Mukaiyama reactions. Attempts to bring the prochiral centre in the silyl enol ether substrates closer to the chiral auxiliary, and thus improve the stereofacial selectivity, proved unsuccessful. The silyl enol ether derivatives, however, display interesting fragmentation patterns in their electron impact mass spectra, which were investigated using a combination of high resolution MS, comparative low resolution MS and metastable peak analysis.

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13

O'Neill, Bridget. "Syntheses of novel 2-oxo esters : enzyme substrates designed for asymmetric synthesis." Thesis, University of Bristol, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.261316.

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14

Chenault, Darrell Vincent. "Total synthesis of 6-chlorodemethyllavendamycin esters and amides." Virtual Press, 1998. http://liblink.bsu.edu/uhtbin/catkey/1115748.

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The synthesis of several 6-Chlorodemethyllavendamycin analogs and their chemistry are described. In this investigation the following compounds were prepared:6-Chlorodemethyllavendamycin methyl ester, 6-Chlorodemethyllavendamycin ethylester, 6-Chlorodemethyllavendamycin butyl ester, 6-Chlorodemethyllavendamycin isoamyl ester, 6-Chlorodemethyllavendamycin octyl ester, and 6-Chlorodemethyllavendamycin amide. Pictet Spengler condensation of 7-amino-6-chloro-2-formylquinoline-5,8-dione with tryptophan methyl ester, tryptophan ethyl ester, tryptophan butyl ester, tryptophan isoamyl ester, tryptophan octyl ester, and tryptophan amide in anisole afforded the compounds. 7-amino-6-chloro-2-formylquinoline-5,8-dione was prepared according to the following general procedures.The first step is the nitration of 8-Hydroxy-2-methylquinoline. 8-Hydroxy-2methylquinoline is reacted with 70% mixture of HNO3/H2SO4 to produce 5,7-dinitro-8hydroxy-2-methylquinoline. The next step requires hydrogenation and acylation. 5,7Dinitro-8-hydroxy-2-methylquinoline was reduced by H2/Pd-C in the presence of HCl and H20 filtered and then treated with sodium sulfite, sodium acetate and acetic anhydride to yield 5,7-diacetamido-8-acetoxy-2-methylquinoline. 5,7-Diacetamido-8-acetoxy-2methylquinoline was oxidized by potassium dichromate to produce 7-acetamido-2methylquinoline-5,8-dione. 7-Acetamido-2-methylquinoline-5,8-dione was chlorinated using hydrogen chloride gas in dry methanol producing 7-amino-6-chloro-2methylquinoline-5,8-dione. Treatment of 7-amino-6-chloro-2-methylquinoline-5,8-dione with selenium dioxide, under reflux in 1,4-dioxane produced 7-amino-6-chloro-2formylquinoline-5, 8-dione.All structures were confirmed by 'H NMR, IR, EIMS, and HRMS.
Department of Chemistry

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15

Haddad, Jalal. "Synthesis and chemistry of some quinoline-5,8-diones." Virtual Press, 1994. http://liblink.bsu.edu/uhtbin/catkey/917048.

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The synthesis of several 7-substituted analogs of 2-methylquinoline-5,8-dione and their chemistry are described. In this investigation the following compounds were prepared.5,7-Diformamido-8-hydroxy-2-methylquinoline (207), 7-formamido-2methylquinoline-5,8-dione (199), 7-acetamido-2-methylquinoline-5,8-dione (6), 7-isobutyramido-2-methylquinoline-5,8-dione (200), 7-amino-2-methylquinoline-5,8-dione (210), 7-amino-6-chloro-2-methylquinoline-5,8-dione (213), 7-methoxy-2-methylquinoline5,8-dione (214), 7-ethoxy-2-methylquinoline-5,8-dione (215), 7-isopropyloxy-2methylquinoline-5,8-dione (216), 7-amino-5-ethyl-5-hydroxy-2-methylquinoline-8-one (218), 7-acetamido-5-ethyl-5-hydroxy-2-methylquinoline-8-one (220), and 7-chloro-2methylquinoline-5,8-dione (222).Trimetylacetic formic anhydride (206) was prepared according to McGarvy,s 68 method from treatment of sodium formate (204) and trimethylacetyl chloride (203) in the presence of poly (4-vinylpyridine-N-oxide) (205) as catalyst. 7-Formamido-2methylquinoline-5,8-dione (199) was prepared according to the following general procedure. 8-Hydroxy-2-mehylquinoline (5) was reacted with a 70% mixture of HNO3/H2SO4 to produce 5,7-dinitro-8-hydroxy-2-methylquinoline (18). Compound 18 was reduced by H2/Pd-C in the presence of HCl and then the resulting 5,7-diamino-8-hydroxy-2 methylquinolin-5,8-dione hydrochloride salt (198) reacted with trimethylacetic formic anhydride to produce 5,7-diformamido-8-hydroxy-2-methylquinoline-5,8-dione (207). Compound 207 was treated with a solution of potassium dichromate in acetic acid-water mixture to give product 199.7-Acetamido-2-methylquinoline-5,8-dione (6) was prepared from reaction of a solution of 198 with acetic anhydride in the presence of sodium acetate and sodium sulfite followed by oxidation with potassium dichromate in acetic acid-water solution. 7-Isobutyramido-2methylquinoline-5,8-dione (200) was prepared according to following procedure. Treatment of a solution of 198 with isobutyric anhydride in the presence of sodium acetate and sodium sulfite afforded 5,7-diisobutyramido-8-isobutyroxy-2-methylquinoline (212). Partial hydrolysis of 212 in boiling methanol-water mixture gave 5,7-diisobutyramido-8-hydroxy-2methylquinoline (211). Oxidation of 211 by a solution of potassium dichromate in acetic acid-water mixture afforded product 200.7-amino-2-methylquinoline-5,8-dione (210) was prepared from alcoholysis of 7-acylamino-2-methylquinoline-5,8-diones 6, 199,and 200 with methanol and sulfuric acid. 7-Alkoxy-2-methylquinoline-5,8-diones 214, 215, and 216 were prepared from reaction of 7-acetamido compound 6 with alcohols in the presence of sulfuric acid. Reaction of 7-acylamino compounds 6, 199, and 200 with methanol in the presence of hydrogen chloride gas at 60°C afforded 7-amino-6-chloro-2-methylquinoline-5,8-dione (213).Reaction of compound 210 with diethylaluminum cyanide gave 7-amino-5-ethyl-5hydroxy-2-methylquinoline-8-one (218). The same reaction was carried out on compound 6 to give 7-acetamido-5-ethyl-5-hydroxy-2-methylquinoline-8-one (220).1-[(tert-Butyldimethylsilyl)oxy]-2-methyl-l-aza-1,3-butadiene (4) was prepared from treatment of methyl vinyl ketone (210) and t-butylmethylsilylhydroxylamine (202) in dichloromethane in the presence of molecular sieves. Cycloaddition reaction of a solution of 4 in dichloromethane with 2,6-dichloro-1,4-benzoquinone (221) in sealed tube afforded 7-chloro-2-methylquinoline-5,8-dione (222).
Department of Chemistry

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16

Zehr, Peter S. "Synthesis of novel alkaloids using squaric acid esters." Morgantown, W. Va. : [West Virginia University Libraries], 2005. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=4411.

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Thesis (Ph. D.)--West Virginia University, 2005.
Title from document title page. Document formatted into pages; contains xvii, 207 p. : ill. Includes abstract. Includes bibliographical references (p. 97-101).

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17

Edelstein, Emma Kate. "Enantioselective synthesis and stereospecific transformations of organoboronic esters." Thesis, Boston College, 2018. http://hdl.handle.net/2345/bc-ir:108038.

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Thesis advisor: James P. Morken
This dissertation details the development of several enantioselective or stereospecific transformations involving organoboronic esters. Chapter one will introduce electrophile-induced boronate rearrangements which underpins much of the reactivity that will be discussed in subsequent chapters. In chapter two the conjunctive cross-coupling reaction is presented. Its development and application to the synthesis of non-racemic boronic esters, along with its application to the synthesis of enantioenriched allylic boronic esters, will be discussed. In chapter three the cross-coupling of geminal bis(boronic) esters is introduced and the development of a method to employ them in cross-coupling with alkenyl bromides, affording enantioenriched substituted allylic boronic esters is outlined. In chapter four we highlight the utility of allylic boronic esters, and detail the development of a cross-coupling reaction that involves the use of these substrates and halide electrophiles to furnish enantiomerically enriched products containing all carbon quaternary stereocenters. Finally, in chapter five we describe the development of a metalfree amination reaction of organoboron compounds, which is able to deliver otherwise difficult-to-access enantiomerically enriched α-tertiary amines
Thesis (PhD) — Boston College, 2018
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Chemistry

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18

Taher, Salam Ghafour. "Synthesis of myobacterial wax esters and related compounds." Thesis, Bangor University, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.664599.

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Mycobacteria are present in a wide range of environments. They contain characteristic complex mixtures of mycolic acids in the cell wall together with other lipids. The high resistance of mycobacteria to the majority of antibiotics, therapeutic agents and disinfectants is thought to be related to the unique structure of the mycobacterial cell wall. Mycolic acids are high molecular weight a-alkyl-branched B-hydroxy long chain fatty acids (60-90 carbon atoms). Different species of Mycobacteria may produce different classes of mycolic acids including a-, methoxy, keto, and wax ester mycolic acids, each present as mixtures of homologues. These may contain different functional groups such as ester, keto, methoxy, hydroxyl, and alkene. The most reported lipids present in the cell wall are sugar esters, e.g mycolyl trehalose esters. These mycolic acids and mycolyl trehalose esters show very interesting toxic and immunological properties; these offer considerable potential for application in the detection, control, and treatment of mycobacterial infection, and also in developing sensors for detection of disease. This study will seek to explore these potentials. This project involved the synthesis of several mycolic acids, wax esters and trehalose esters. The biological activities of these synthetic compounds would be studied, particularly their suitability as specific antigens to detect mycobacterial infections in serodiagnostic assays. The objectives of the project are discussed in four parts. The first part of this project involved the first synthesis of wax ester (A) and its corresponding ω-carboxymycolic acid (B), one component of the complex mixture isolated from Mycobacterium avium. Once the synthesis had been optimised, synthesis of the wax ester (C) and its corresponding ω-carboxymycolic acid (D) were also achieved, the latter compounds being isolated from Mycobacterium gordonae. In addition the wax ester (E) was also prepared introducing longer chain lengths than the natural wax ester. This was to study whether or not the chain length has any effect on the biological activities.

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19

Tatebe, Caleb J. "Synthesis of Sugar-Derived Esters and Carbamate Compounds." Youngstown State University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1409833972.

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Zaluski, Jordan A. "Improved Synthesis of Bis (2,2,2-trifluoroethyl) Phosphono Esters." Youngstown State University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1471443290.

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21

黃志輝 and Chi-fai Wong. "Synthesis and physical properties of some allenic fatty esters." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1993. http://hub.hku.hk/bib/B3123396X.

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22

Karki, Rajesh. "Total synthesis of oxygenated lavendamycin analogs." Virtual Press, 1998. http://liblink.bsu.edu/uhtbin/catkey/1115420.

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The synthesis of 7-acetyl-11'-benzyloxylavendamycin methyl ester (47), 7acetyl-11'-hydroxylavendamycin methyl ester (48), 11'-hydroxylavendamycin methyl ester (49), 11'-benzyloxylavendamycin methyl ester (50), are described. Pictet-Spengler condensation of 7-N-acetyl-2-formylquinoline-5,8-dione (26) with 5-benzyloxytrytophan methyl ester (45) or 5-hydroxytryptophan methyl ester (46) in dry xylene or anisole directly afforded lavendamycin analogs 47 or 48. Compound 49 was obtained by hydrolysis of 48 with 70% H2SO4 - H2Osolution. Compound 50 was obtained by hydrolysis of 47 with sodium carbonate solution.Aldehyde 26 was prepared according to the following general procedure. Nitration of 8-hydroxy-2-methylquinoline (28) yielded 8-hydroxy-2-methyl5,7-dinitroquinoline (29). Compound 29 was then hydrogenated and acylated with acetic anhydride to yield 5,7-bis(diacetamido)-8-hydroxy-2methylquinoline (31). Compound 31 was oxidized to give 5,8- dione 25 by using potassium dichromate. Treatment of compound 25 with selenium dioxide in refluxing 1,4-dioxane yielded compound 26.3 (Isopropylaminoethylidene)-6,7-dimethoxyindole (39) was prepared via the following procedure. Acylation of vanillin (32) with acetic anhydride yielded acetylvanillin (33). Compound 33 was nitrated and hydrolyzed to give 2nitrovanillin (35). Compound 35 was then methylated using dimethyl sulfate to produce 2-nitroveratric aldehyde (36). Condensation of compound 36 with nitromethane yielded 3,4-dimethoxy-2-f3-nitrostyrene (37). Ammonium formate reductive cyclization of compound 37 in refluxing methanol in the presence of a catalytic amount of 10% palladium on charcoal yielded 6,7dimethoxyindole (38). Electrophilic substitution reaction of compound 38 with ethylideneisopropylamine (41) in dry toluene yielded compound 39.Methyl (2RS, 3SR)-2-amino-3-[3-(5-benzyloxyindolyl)]butanoate (45) and methyl (2RS, 3SR)-2-amino-3-[3-(5-hydroxyindolyl)]butanoate (46) were obtained following the procedure described below. Electrophilic substitutionreaction of 5-bezyloxyindole (40) with ethylideneisopropylamine (41) in dry toluene yielded 3-(isopropylaminoethylidene)-5-benzyloxyindole (42). Condensation of compound 42 with methyl nitroacetate (43) in dry toluene gave methyl 3-[3-(5-benzyloxyindolyl)]3-nitrobutanoate (44). Hydrogenation of compound 44 in the presence of Raney nickel and trifluoroacetic acid in ethanol yielded methyl (2RS, 3SR)-2-amino-3-[3-(5-benzyloxyindolyl)] butanoate (45). Hydrogenation of compound 44 in the presence of 10% palladium on charcoal and trifluoroacetic acid in ethanol yielded methyl (2RS, 3SR)-2-amino-3-[3-(5-hydroxyindolyl)] butanoate (46).The structures of the novel compounds were confirmed by 1H NMR, IR, and HRMS or elemental analysis.
Department of Chemistry

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23

Sheth, Ritesh B. "Development of new synthetic methodologies and the synthesis of natural products." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 101 p, 2010. http://proquest.umi.com/pqdweb?did=1993336351&sid=2&Fmt=2&clientId=8331&RQT=309&VName=PQD.

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Kling, Marcel Robert. "Synthesis of very long chain fatty acid methyl esters /." Title page, table of contents and abstract only, 1991. http://web4.library.adelaide.edu.au/theses/09PH/09phk65.pdf.

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25

Milsom, Greig. "Synthetic approaches to the asymmetric synthesis of #alpha#-keto and #beta#-hydroxy esters." Thesis, Kingston University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.285949.

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Apsimon, Megan K. "A novel enantioselective synthesis of allenic esters and amides." Thesis, University of Ottawa (Canada), 2009. http://hdl.handle.net/10393/28447.

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In recent years, allenes have become recognized as useful synthons in organic chemistry. Their unique orthogonal pi-bond system can be used in a variety of regio- and stereoselective carbon-carbon bond-forming reactions. Chiral allenes also have the ability to transfer their chirality to one or more new chiral centres. Despite this usefulness, the synthesis of chiral allenes is quite limited. Most methods to synthesize asymmetric allenes require chirality transfer from a pre-formed chiral centre, while only a handful of methods exists which form an asymmetric allene from achiral starting materials. We have discovered a new method for synthesizing chiral allenes using achiral 3-alkynoates or 3-alkynamides. Treatment of a propargyl carbonyl compound with a catalytic silver source and a chiral Lewis Acid in the presence of a weak amine base results in the formation of chiral allenic esters and amides. Initial reactions with 3- alkynoates lead to the discovery of AgSbF6 and (R)-(S)-JOSIPHOS as the ideal catalyst system, and N-methylmorpholine as the base. When the reaction was performed in a mixture of methanol/THF, this resulted in the formation of allenes with ee values higher than 90%. The reactions did not complete, however, resulting in a mixture of alkynes and allenes which was not separable by chromatography. This problem was solved by applying the same methodology to 3-alkynamides. Within an hour at 0°C, the reaction was finished, and the alkynes and allenes could easily be separated chromatographically. Nine different allenic amides were synthesized, in 27-95% yield, and 90-99% ee. Once the allenes were synthesized, we determined the absolute stereochemistry, discovering that our methodology formed the (S)-allenes. We did this by transforming the allenes to a known butenolide via and iodolactionization reaction and removal of the iodine. By comparing the experimental optical rotation to the known optical rotation, we were able to determine the absolute stereochemistry. This was also confirmed by applying the Lowe-Brewster rule, a rule which applies only to allenes. In allenes, the absolute stereochemistry and axial helicity of the compound can be used to predict the direction of the optical rotation, and vice versa.

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Webster, Matthew Peter. "Multiple Homologations of Boronic Esters and Applications in Synthesis." Thesis, University of Bristol, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.520203.

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28

Betke, Tobias [Verfasser]. "Chemoenzymatic synthesis of nitriles and lubricant esters / Tobias Betke." Bielefeld : Universitätsbibliothek Bielefeld, 2019. http://d-nb.info/1196638330/34.

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29

Kutuk, Halil. "The synthesis and mechanisms of hydrolysis of iminosulfonate esters." Thesis, University of Essex, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.386940.

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30

Silcock, Alan J. "Enantioselective synthesis and cyclisation studies of 2-hydroxy esters." Thesis, University of Bristol, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.299530.

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31

Nascimento, Vera LÃcia Viana do. "Development of chemical process for synthesis of polyunsaturated esters." Universidade Federal do CearÃ, 2014. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=13741.

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Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico
This work aimed to develop refining processes, chemical alcoholysis followed by separation of fatty acids using the complexation with urea technique for the synthesis of poly-unsaturated esters from waste of fish oils. The special crude fish oil was purchased from Company Campestre - SÃo Paulo. Initially this oil has undergone a process of physical and chemical refining. From the refined oil, an alcoholysis process was carried out to obtain the mixture of free fatty acids. From the hydrolyzed material were obtained 32.78% p/p of PUFAs against 19.73% p/p of ω-3 concentrates. The free fatty acids were separated using the complexation with urea technique. The best operating conditions for separation of the fatty acids was: ratio 7:1 (urea / oil) and the crystallization temperature at -23ÂC for a time of 20 hours. After treatment of the material, the total PUFAs production was 47.87%, a ω-3 concentration of 27.59% with a saturated fraction of 4.48%. When the temperature was raised to -10ÂC, the PUFAs production was halved, reaching the value of 28.08% and 25.49% of ω-3 which was slightly altered and a saturated fraction of 42.44%. For the ester synthesis was mounted a statistical factor of two levels in order to determine the parameters which optimized the process. In the synthesis phase, the combination of temperature, glycerin concentration and catalyst was significant, and it was observed a greater influence of the glycerin concentration due to the excessive use of glycerin to favor the formation of the ester. After the analysis of the kinetic results was observed that the interactions temperature-glycerin and temperature-glycerin-catalyst were not significant (below 95%). The response interaction graphic showed the least free fatty acids index after one hour of reaction, and that the greater interaction was glycerin (5%)-catalyst (3%). It was concluded that the yields to obtain the polyunsaturated ω-3 and ω -6 from the waste of fish oil were satisfactory (85,3%). Therefore, it is concluded that it is feasible the synthesis of polyunsaturated esters of marine oils from fish waste, because this technology provides important results to avoid environmental impacts, reduce imports of fish oils and, consequently, reduce improper fishing. The aquaculture industry may be stocked with diets enriched with EPA and DHA for shrimp and fish farming, besides contributing to supply ω-3 for nutraceutical purposes.
Este trabalho teve o objetivo de desenvolver os processos de refino, alcoÃlise quÃmica seguida da separaÃÃo dos Ãcidos graxos utilizando a tÃcnica da complexaÃÃo com urÃia para a sÃntese de Ãsteres poli-insaturados a partir de resÃduos de Ãleos de pescado. O Ãleo bruto especial de peixe foi adquirido da Empresa Campestre â SÃo Paulo. Inicialmente este Ãleo sofreu um processo de refino fÃsico e quÃmico. A partir do Ãleo refinado, foi realizado um processo de alcoÃlise para se obter a mistura de Ãcidos graxos livres. Do material hidrolisado, foram obtidos 32,78% p/p de PUFAs contra 19,73% p/p de concentrados de ω-3. Os Ãcidos graxos livres foram separados utilizando-se a tÃcnica da complexaÃÃo com urÃia. As melhores condiÃÃes operacionais para separaÃÃo dos Ãcidos graxos foram: a relaÃÃo 7:1 (urÃia/Ãleo) e a temperatura de cristalizaÃÃo a -23ÂC por um tempo de 20 horas. ApÃs o tratamento do material, a produÃÃo total de PUFAs foi de 47,87%, uma concentraÃÃo de ω-3 de 27,59% com uma fraÃÃo saturada de 4,48%. Quando se elevou a temperatura para -10ÂC, a produÃÃo de PUFAs reduziu pela metade, atingindo o valor de 28,08% e 25,49% de ω-3, que pouco foi alterada e uma fraÃÃo de saturados de 42,44%. Para a sÃntese do Ãster de glicerina foi montado um fatorial estatÃstico de dois nÃveis a fim de se determinar os parÃmetros que otimizaram o processo. Na fase de sÃntese, a conjugaÃÃo de temperatura, concentraÃÃo de glicerina e catalisador foram significantes, tendo sido observado uma maior influÃncia da concentraÃÃo de glicerina, em virtude do uso excessivo de glicerina para favorecer a formaÃÃo do Ãster. ApÃs as anÃlises dos resultados cinÃticos, foi observado que as interaÃÃes temperatura-glicerina e temperatura-glicerina-catalisador nÃo foram significantes (abaixo de 95%). O grÃfico da interaÃÃo para resposta mostrou o menor Ãndice de Ãcidos graxos livres apÃs uma hora de reaÃÃo, e que a maior interaÃÃo foi glicerina (5%)-catalisador (3%). Foi concluÃdo que os rendimentos para obtenÃÃo dos poli-insaturados ω-3 e ω -6 dos resÃduos de Ãleo de pescado foram satisfatÃrios (85,3%). Conclui-se, portanto, que Ã viÃvel a sÃntese de Ãsteres poli-insaturados de Ãleos marinhos a partir de rejeitos de pescados, pois esta tecnologia proporciona resultados importantes para evitar impactos ambientais, diminuir as importaÃÃes de Ãleos de peixe e, consequentemente, reduzir a pesca indevida. O setor aquÃcola poderÃ ser abastecido com raÃÃes enriquecidas com EPA e DHA para camarÃes e peixes de cultivo, alÃm de contribuir para oferta de ω-3 para fins nutracÃuticos.

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32

Wong, Chi-fai. "Synthesis and physical properties of some allenic fatty esters /." [Hong Kong : University of Hong Kong], 1993. http://sunzi.lib.hku.hk/hkuto/record.jsp?B13597437.

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33

Carlisle, Lemuel Robert II. "Novel Approaches Toward the Synthesis of Bis (2,2,2 trifluroethoxy) Phosphono Esters." Youngstown State University / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1198202999.

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34

Ebrahimian, G. Reza. "Total synthesis of analogs of lavendamycin." Virtual Press, 2003. http://liblink.bsu.edu/uhtbin/catkey/1265456.

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35

LaLama, Matthew. "Rhodium-Catalyzed Decomposition of Carbohydrate Diazo Esters." Youngstown State University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1532881612843223.

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36

Cay, J. A. "Synthesis of sugar derivatives by the cyclisation of allene esters." Thesis, University of Newcastle Upon Tyne, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.413012.

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37

Tarantino, Riccardo. "Lipase-catalyzed synthesis of esters and amides for cosmetic uses." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2022.

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This work focuses on the Lipase-catalyzed synthesis of esters and amides of great interest for the cosmetic sector, by employing enzymes Lipozyme® 435 and Novozym® 435, respectively. The esterification reactions yielded very high conversion of substrates in solvent-free systems within a short time interval. Regarding the synthesis of amides, Lauric and Oleic acid monoethanolamine (LMEA and OMEA) were successfully synthetized both with and without the use of organic solvents. The most promising results were obtained through the transacylation reactions in tert-butanol between the ethyl esters of fatty acids and monoethanolamine, with remarkable yields in few reaction hours. The synthesis of the same compounds in solvent-free systems led to lower amount of product due to the formation of undesired highly viscous substances: the finest results were obtained by using lauric acid and methyl oleate as acyl donors for LMEA and OMEA, respectively. At last, a two-step procedure to synthesize a pseudo-ceramide is reported, and the high purity thereof corroborated by 1H NMR analysis.

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38

Rajagopal, Thivisa. "Synthesis of Single Isomer Trisubstituted Olefins from beta-chloro-alpha-iodo-alpha, beta-Unsaturated Esters and Alkynyl Esters." Thesis, University of Ottawa (Canada), 2010. http://hdl.handle.net/10393/28552.

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A convenient method to synthesize regiospecific and stereoselective trisubstituted olefins bearing three substitutents with various functionalities is disclosed. A unique olefin template such as (E)-beta-chloro-alpha-iodo-alpha,beta-unsaturated esters cross-couple with 9-alkyl-9-BBN to produce single isomer trisubstituted olefins using palladium-catalyzed Suzuki-Miyaura cross-coupling reaction. This methodology can be further expanded to introduce various alkyl groups at the beta-position. The mechanism is somewhat unusual as it involves two catalytic cycles with an allenoate intermediate to explain the observed stereochemistry and protonolysis of that intermediate produces the key product, (E)-beta-chloro-alpha,beta-unsaturated ester. The protonolysis is mediated by the presence of H2O in the inorganic base, K3PO4·H2O.* Similarly, another method has been developed to synthesize trisubstituted olefins using the alkynyl ester and 9-alkyl-9-BBN. This process also has a broad scope to introduce various alkyl groups at the beta-position. The mechanism currently proposed involves an oxidation of palladium to form H-[Pd]-OH species. This was confirmed based on the importance of water in the catalytic system and the isotopic experiments also confirmed the olefinic hydrogen at the alpha-position arises from the water itself. Following the formation of H-[Pd]-OH, syn carbopalladation to the alkynyl ester creates the hydroxyl palladium vinyl intermediate. However, this mechanism does not explain the observed stereochemistry. A more detailed study is required regarding this mechanism.* *Please refer to dissertation for diagrams.

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39

Ross, Robert John. "Synthesis of an ingenane A/B-ring analogue : a model study for the total synthesis of ingenol /." The Ohio State University, 1986. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487266362337137.

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40

鄭一楓 and Yi-Feng Zheng. "A study of the synthesis and properties of some oxiranyl and thiirangllong chain fatty acid esters and the production of furanyl derivativesfrom the seed oil of biota orientalis." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1988. http://hub.hku.hk/bib/B31209063.

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41

老洪柏 and Hongbai Lao. "A study of the synthesis and properties of some long chain fatty acid esters containing azido, amino, amido and amino acid residues and theanalysis of some seed oils used in Chinese medicine." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1989. http://hub.hku.hk/bib/B31208691.

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42

林立基 and Lap-kay Wilson Lam. "Organometallic reactions involving long chain fatty acid esters." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1987. http://hub.hku.hk/bib/B31231196.

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43

Tsukamoto, Junko, Sophie Heabel, Gustavo P. Valenca, Martin Peter, and Telma Franco. "Enzymatic direct synthesis of acrylic acid esters of mono- and disaccharides." Universität Potsdam, 2008. http://opus.kobv.de/ubp/texte_eingeschraenkt_verlag/2010/4265/.

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BACKGROUND: There is an increased need to replace materials derived from fossil sources by renewables. Sugar-cane derived carbohydrates are very abundant in Brazil and are the cheapest sugars available in the market, with more than 400 million tons of sugarcane processed in the year 2007. The objective of this work was to study the preparation of sugar acrylates from free sugars and free acrylic acid, thus avoiding the previous preparation of protected sugar derivatives, such as glycosides, or activated acrylates, such as vinyl acrylate. RESULTS: Lipase catalyzed esterification of three mono- and two disaccharides with acrylic acid, in the presence or absence of molecular sieves was investigated. The reactions were monitored by high-performance liquid chromatography (HPLC) and the products were analyzed by matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) mass spectrometry. The main products are mono- and diacrylates, while higher esters are formed as minor products. The highest conversion to sugar acrylates was observed for the D-glucose and D-fructose, followed by D-xylose and D-maltose. Molecular sieves had no pronounced effect on the conversion CONCLUSIONS: A feasible method is described to produce and to characterize sugar acrylates, including those containing more than two acrylate groups. The process for production of these higher esters could potentially be optimized further to produce molecules for cross-linking in acrylate polymerization and other applications. The direct enzymatic esterification of free carbohydrates with acrylic acid is unprecedented.

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44

Carlisle, Lemuel R. "Novel approaches toward the synthesis of bis(2,2,2-trifluroethoxy) phosphono esters /." Connect to resource online, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1198202999.

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45

Butcher, Jane Lesley. "Structural studies and synthesis of mesomorphic esters containing the thiophene nucleus." Thesis, Nottingham Trent University, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.293852.

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Chapman, Robert. "Sustainable methodology for the synthesis of amides, esters and polypropionate fragments." Thesis, University of Bath, 2017. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.715298.

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This thesis presents research into the development of sustainable methodology for the synthesis of amides, esters and polypropionate fragments. As well as a literature review of efficient natural product synthesis. Acylals are a known class of reagent that have been utilized within literature for a wide range of synthetic methodologies. Herein we present acylals as new highly active reagents for the N-/O-acylation of amines and alcohol nucleophiles for the synthesis of a range of formamides, acetamides, formate esters and acetate esters. It has been demonstrated that a range of acyl groups can be transferred including short and long chain alkyls, acryloyl, benzoyl, phenyl acetyl and biologically important trifluoroacetyl group, thus enabling the synthesis of a range of benzylamides and esters. These acylation reagents have also been shown to demonstrate inherent N-/O- selectivity towards the amine and alcohol groups of serine methyl ester. The scope and limitations of these reagents of the use of acylals has been investigated through the N-formylation of a range of unprotected amino acids, and for the synthesis of the biologically important tripeptide f-MLP. As well as the acylation/formylation of the ω-amino residue of a lysine residue within a decapeptide. Finally, it has also been demonstrated that a simple switch in pH from basic to acidic conditions for diols can change from O-acylation to acetal formation. The synthesis of enantiomerically enriched dihydropyrans from the heteo-Diels-Alder reaction of 1-alkoxy dienes and ethyl glyoxalate has been presented. A series of stereoselective derivatisation reactions were developed including, hydroboration, hydrogenation, epoxidation, dihydroxylation and epimerization which procced with stereoselectivity to afford a range of complex enantiomerically enriched polypropionate based building blocks, which are ideally suited for the synthesis of polyketide natural products through a “plug and play” approach. Chemistry has also been presented which makes use of the orthogonally addressable synthetic handles of the pyran building blocks. Utilization of either the masked aldehyde character or the ester functionality present allows for further elaboration of the pyran building blocks by selectively introducing new functionality.

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Knox, T. "Synthesis of long chain esters by a fungal cell-bound enzyme." Thesis, University of the West of Scotland, 1985. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.370509.

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Hesse, Matthew James. "The diastereodivergent synthesis of polysubstituted alkenes through lithiation-borylation methodology." Thesis, University of Bristol, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.633254.

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Simpson, Michael J. "Synthesis of #DELTA#'9-desaturase inhibitors and related cyclopropenes." Thesis, University of Newcastle Upon Tyne, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239574.

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Hernandez, Maria Luisa Escudero. "Enzymatic desymmetrization of prochiral cyclohexanones : synthesis of a non-peptidic NK2 antagonist." Thesis, University of Liverpool, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.343757.

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Dissertations / Theses on the topic 'Esters – Synthesis'

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