Dissertations / Theses: 'Aldehydes'

1

Gayral, Maud. "Novel reactions of aldehydes." Thesis, University of Oxford, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.442958.

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2

Giguère-Bisson, Maxime. "Investigation of transition metal-catalyzed oxidative amidation of aldehydes and aldehyde-alkyne-amine coupling reactions." Thesis, McGill University, 2011. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=103659.

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This thesis describes the investigation of various amino acids derivatives as reagents for copper-catalyzed, silver-catalyzed and iron-catalyzed reactions and the investigation of an enantioselective cobalt-catalyzed aldehyde-alkyne-amine (A3) coupling reaction. The first part focuses on the large-scale optimization of the oxidative amidation of aldehydes in the presence of amine hydrochloride salts as well as our effort to enhance the reaction scope by the use of amino acids derivatives and short peptides. This is then followed by the development of an enantioselective cobalt-catalyzed A3-coupling using binaphthol ligands as a source of chirality. Finally, the last part involves silver-catalyzed alkyne addition to iminoesters as well as silver-catalyzed A3-coupling.
La présente thèse a pour but de présenter l'utilisation de divers dérivés d'acides aminés comme substrats pour plusieurs réactions catalysées par des sels de cuivre, d'argent et de fer, de même que du développement d'une réaction de couplage énantiosélective entre aldéhyde, alcyne et amine (A3) catalysée par des sels de cobalt. La première partie met l'emphase sur l'optimisation à grande échelle d'un procédé d'amidation oxydative d'aldéhydes en présence de sels d'amine ainsi que nos efforts pour adapter cette méthode à des substrats tels que courts peptides et dérivés d'acides aminés. Cela est suivi par le développement d'une réaction de couplage énantiosélective entre aldehyde, alcyne et amine (A3) catalysée par des sels de cobalt misant sur l'utilisation de binaphtols comme ligands chiraux. La dernière partie porte sur l'addition d'alcyne à des iminoesters catalysés par des sels d'argent ainsi que sur des réactions de couplage A3, elles aussi catalysées par des sels d'argent.

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3

Riley, M. Louise. "Alcohol, aldehydes, ageing and cataract." Thesis, University of Oxford, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.260233.

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4

Shand, Neil Charles. "Laser multiphoton spectroscopy of aldehydes." Thesis, Heriot-Watt University, 1997. http://hdl.handle.net/10399/657.

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5

Gustafsson, Jörgen. "Synthesis of cyclohexenedicarbaldehydes and studies of their biologic activity." Lund : Organic Chemistry 2, Lund Institute of Technology, University of Lund, 1994. http://books.google.com/books?id=ULpqAAAAMAAJ.

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6

Kautiainen, Antti. "In vivo dosimetry of aldehydes and studies on the origin of malonaldehyde." Stockholm : Dept. of Radiobiology, Arrhenius Laboratories for Natural Sciences, Stockholm University, 1992. http://catalog.hathitrust.org/api/volumes/oclc/28171674.html.

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7

Yuan, Quan. "Modification of biomolecules by lipoxidation derived aldehydes." online version, 2006. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=case1135006612.

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8

Howe, G. P. "Stereoselective additions to #alpha#,#beta#-epoxy-aldehydes." Thesis, University of Salford, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.381818.

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9

Turp, Edward Robert. "Stereoselective additions to #alpha#,#beta#-epoxy-aldehydes." Thesis, University of Salford, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.245017.

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10

Finkelstein, Erik I. "Regulation of neutrophil function by toxic aldehydes /." For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2002. http://uclibs.org/PID/11984.

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11

Belani, Ramesh. "The catalytic decarbonylation of aldehydes using iron porphyrin complexes." Thesis, University of British Columbia, 1985. http://hdl.handle.net/2429/24476.

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The aim of this project was to investigate the use of iron porphyrin complexes as potential homogeneous catalysts for the decarbonylation of aldehydes. Complexes of the type Fe(TPP)L₂ (where L = n-Bu₃P, PPh₃ or piperidine) were prepared and reacted with CO gas, or with aldehydes as sources of CO. Since the loss of coordinated CO from the Fe(TPP)(CO)(n-Bu₃P) complex was more facile, the bis(n-Bu₃P) phosphine system was studied in more detail. The X-ray structure of FeTPP(n-Bu₃P)₂ Is described, and this includes the first determination of an FeII-P bond distance for a metalloporphyrin. The study using Fe(TPP)L₂ complexes as decarbonylation catalysts was somewhat hindered by the extreme air-sensitivity of the porphyrin complexes in solution. UV/visible spectroscopy and gas chromatography were used to monitor the decarbonylation reactions. The reaction mixtures were analysed by GC/MS. The decarbonylation reactions were characterised by inconsistent turnover numbers and lack of reproducibility; during the decarbonylation of phenylacetaldehyde, bibenzyl was detected. Such factors are indicative of a free radical mechanism, similar to that proposed earlier for related Ru(II) porphyrin systems. The carbonylation of FeTPP(n-Bu₃P)₂ by CO gas was of interest with respect to the catalytic reaction, which must involve formation of a carbonyl complex. The reaction, FeTPP(n-Bu₃P)₂ + CO K [mathematical formula omitted] FeTPP(n-Bu₃P)(CO) + n-Bu₃P was found to have a K value of 0.72 at 29°C, while the temperature dependence of K was studied to obtain the thermodynamic parameters ΔS and ΔH for the equilibrium.
Science, Faculty of
Chemistry, Department of
Graduate

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12

Kirkpatrick, Joanna. "The Strecker degradation and its relationship to flavour in cooked vegetables." Thesis, University of Reading, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.390593.

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13

Ishibashi, Eisuke. "Asymmetric addition of cyanide to aldehydes and imines." Thesis, University of Newcastle Upon Tyne, 2011. http://hdl.handle.net/10443/1185.

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Cyanohydrins are a group of compounds that are widely used in industry as common building blocks for asymmetric synthesis. In this thesis, novel methods of synthesizing chiral cyanohydrins are investigated using complexes of transition metals complexed to salen ligands. To start the project, alternative sources of cyanide were investigated. Unfortunately, this investigation could not uncover a new cyanide source that was more effective than trimethylsilyl cyanide as a substrate for titanium(salen) based catalysts. However, this research has led to the finding that KCN / 18-Crown-6 can be used as a co-catalyst in the addition of ethyl cyanoformate to various aldehydes. This has led to a huge reduction in the amount of catalyst that is required to achieve the same enantiomeric excess. In addition, the diastereoselective synthesis of cyanohydrin derivatives using chiral cyanoformates was made possible for the first time. Some of the cyanohydrins synthesized by the new ethyl cyanoformate route were taken a step further, and their use as chiral building blocks was also studied. By using a palladium based catalyst, α,β,-unsaturated cyanohydrins were converted into amides via a two-step reaction. Research into the Strecker reaction was also carried out using vanadium(V)(salen) complexes as catalysts. In this field, the use of phenols as co-catalysts was discovered, and this has led to a world leading enantiomeric excess.

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14

鄧陽招 and Yeung-chiu Dennis Tang. "Accelerated decomposition of peroxynitrite by Ketones and Aldehydes." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1999. http://hub.hku.hk/bib/B31221701.

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15

Pease, Janet Elizabeth. "Enantioselective additions to aldehydes using TADDOL organocerium reagents." Thesis, University of Liverpool, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.262396.

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16

Allan, John Fraser. "Reactions of amidomagnesium compounds with ketones and aldehydes." Thesis, University of Strathclyde, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.415132.

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17

Antunes, Maria Margarida Feitor Pintão Moreno. "Catalytic routes to convert saccharides to furanic aldehydes." Doctoral thesis, Universidade de Aveiro, 2012. http://hdl.handle.net/10773/12500.

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Doutoramento em Química
The conversion of plant biomass-derived carbohydrates (preferably non-edible) into added-value products is envisaged to be at the core of the future biorefineries. Carbohydrates are the most abundant natural organic polymers on Earth. This work deals with the chemical valorisation of plant biomass, focusing on the acid-catalysed conversion of carbohydrates (mono and polysaccharides) to furanic aldehydes, namely 2-furaldehyde (Fur) and 5-hydroxymethyl-2-furaldehyde (Hmf), which are valuable platform chemicals that have the potential to replace a variety of oil derived chemicals and materials. The investigated reaction systems can be divided into two types depending on the solvent used to dissolve the carbohydrates in the reaction medium: water or ionic liquid-based systems. The reaction temperatures were greater than 150 ºC when the solvent was water, and lower than 150 º C in the cases of the ionic liquid-based catalytic systems. As alternatives to liquid acids (typically used in the industrial production of Fur), solid acid catalysts were investigated in these reaction systems. Aiming at the identification of (soluble and insoluble) reaction products, complementary characterisation techniques were used namely, FT-IR spectroscopy, liquid and solid state NMR spectroscopy, TGA, DSC and GC´GC-ToFMS analyses. Complex mixtures of soluble reaction products were obtained and different types of side reactions may occur. The requirements to be put on the catalysts for these reaction systems partly depend on the type of carbohydrates to be converted and the reaction conditions used. The thermal stability is important due to the fact that formation of humins and catalyst coking phenomena are characteristically inherent to these types of reactions systems leading to the need to regenerate the catalyst which can be effectively accomplished by calcination. Special attention was given to fully inorganic nanoporous solid acids, amorphous or crystalline, and consisting of nano to micro-size particles. The investigated catalysts were silicoaluminophosphates, aluminosilicates and zirconium-tungsten mixed oxides which are versatile catalysts in that their physicochemical properties can be fine-tuned to improve the catalytic performances in the conversion of different substrates (e.g. introduction of mesoporosity and modification of the acid properties). The catalytic systems consisting of aluminosilicates as solid acids and water as solvent seem to be more effective in converting pentoses and related polysaccharides into Fur, than hexoses and related polysaccharides into Hmf. The investigated solid acids exhibited fairly good hydrothermal stabilities. On the other hand, ionic liquid-based catalytic systems can allow reaching simultaneously high Fur and Hmf yields, particularly when Hmf is obtained from D-fructose and related polysaccharides; however, catalyst deactivation occurs and the catalytic reactions take place in homogeneous phase. As pointed out in a review of the state of the art on this topic, the development of truly heterogeneous ionic liquid-based catalytic systems for producing Fur and Hmf in high yields remains a challenge.
Os carboidratos constituem os polímeros naturais mais abundantes na Terra, e a sua valorização química é de grande interesse no contexto das biorefinarias. O objetivo deste trabalho centrou-se na conversão de carboidratos (monossacarídeos e polissacarídeos) em 2-furaldeído (Fur) e 5-hidroximetil-2-furaldeído (Hmf) na presença de catalisadores ácidos, em reatores descontínuos. Fur e Hmf são considerados compostos “plataforma” porque podem ser convertidos numa grande variedade de produtos químicos e materiais (alternativos aos derivados do petróleo). Testaram-se catalisadores ácidos heterogéneos como alternativa aos ácidos minerais que são comumente usados como catalisadores homogéneos para a produção industrial do Fur. Por outro lado utilizou-se água ou um líquido iónico como solvente para a dissolução dos carboidratos no meio reacional. As temperaturas reacionais foram superiores a 150 ºC quando o solvente era a água, e inferiores a 150 ºC no caso de líquidos iónicos. Com o intuito de identificar os produtos reacionais (solúveis e insolúveis), utilizaram-se diferentes técnicas nomeadamente espetroscopia de infravermelho, espetroscopia de RMN de estado líquido e sólido, TGA, DSC e GCxGC-ToFMS. Obtiveram-se misturas complexas de produtos reacionais e discutiram-se aspetos mecanísticos. A estabilidade térmica do catalisador é importante uma vez que a formação de matéria carbonácea insolúvel é característica destes sistemas reacionais tornando-se necessário proceder à regeneração do catalisador por calcinação. Os catalisadores testados foram ácidos inorgânicos nanoporosos, cristalinos ou amorfos, com tamanho de partícula nano ou micrométrico, especificamente silicoaluminofosfatos, aluminossilicatos e óxidos mistos de zircónio e tungsténio. Estes tipos de materiais são versáteis uma vez que as suas propriedades físicoquímicas podem ser modificadas no sentido de melhorar os seus desempenhos catalíticos na conversão de diferentes tipos de substratos (ex. através da criação de mesoporos nos materiais e/ou modificação das propriedades ácidas). Os materiais testados exibiram melhores desempenhos catalíticos para a conversão de pentoses em Fur do que para a de hexoses em Hmf, quando o solvente era a água. Em suma, os catalisadores apresentaram boa estabilidade hidrotérmica. No caso dos sistemas reacionais à base de líquidos iónicos foram verificados elevados rendimentos em Fur e Hmf. especialmente quando os substratos eram a D-frutose ou polissacarídeos relacionados. Contudo, os catalisadores sofreram desativação tal que as reações catalíticas ocorreram em fase homogénea. Conforme explicado numa revisão bibliográfica sobre o estado da arte da conversão catalítica de carboidratos em Fur e Hmf usando líquidos iónicos, o desenvolvimento de sistemas catalíticos heterogéneos à base de líquidos iónicos representa um grande desafio.

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18

Boßmeyer, Jens. "Studies of aldehydes in an atmosphere simulation chamber." [S.l. : s.n.], 2006. http://nbn-resolving.de/urn:nbn:de:bsz:16-opus-63079.

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19

Tang, Yeung-chiu Dennis. "Accelerated decomposition of peroxynitrite by Ketones and Aldehydes /." Hong Kong : University of Hong Kong, 1999. http://sunzi.lib.hku.hk/hkuto/record.jsp?B20897145.

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20

Suloff, Eric Charles. "Sorption Behavior of an Aliphatic Series of Aldehydes in the Presence of Poly(ethylene terephthalate) Blends Containing Aldehyde Scavenging Agents." Diss., Virginia Tech, 2002. http://hdl.handle.net/10919/29917.

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The quality of many beverages and food products is compromised by the presence of low molecular weight aldehydes. Aldehydes are commonly formed during storage by the oxidation of lipids or are introduced as migrants from polymeric packaging material. The objective of this project was to evaluate the effectiveness of three aldehyde scavenging agents, blended into poly(ethylene terephthalate) (PET) films, in removing an aliphatic series of aldehydes from an acidified aqueous model solution (pH 3.6) during storage. Aldehyde concentration in solution was determined by an improved high performance liquid chromatography method involving the formation of aldehyde-hydrazine complexes by 2,4-dinitrophenylhydrazine. Storage of 25 μM mixtures of acetaldehyde, propionaldehyde, butyraldehyde, valeraldehyde, and caproaldehyde in contact with PET films blended with 5% poly(m-xylylene adipamide) (nylon MXD6), D-sorbitol, or alpha-cyclodextrin reduced the concentration of each aldehyde in solution by 21 to 90% after 14 days of exposure. D-sorbitol and alpha-cyclodextrin aldehyde scavenging PET films were the most effective treatments for the reduction of aldehydes from solution showing similar average reductions for the five aldehyde species of 11.4 and 13.8 μM, respectively. PET films blended with nylon MXD6 were less effective in removing aldehydes from solution showing an average reduction of 8.4 μM for the five aldehyde species. However, nylon MXD6 proved to the most efficient aldehyde scavenging agent tested. D-sorbitol and alpha-cyclodextrin blends include 45 and 17 times more aldehyde scavenging sites then nylon MXD6 blends, but only showed 26 and 39% improvements in aldehyde scavenging ability when compared to nylon MXD6 blends. Aldehyde scavenging films demonstrated selective scalping preferring smaller molecular weight aldehydes, such as acetaldehyde, propionaldehyde, and butyraldehyde, more than larger aldehydes, valeraldehyde and caproaldehyde. Partition coefficients for smaller aldehydes were 3 to 6 times greater for aldehyde scavenging films then control film.
Ph. D.

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21

MHAMDI, FARIDA. "Nouvelle synthese des monomeres de la lignine (aldehydes et alcools cinnamiques). Etude electrochimique et radiolytique du mecanisme de dimerisation des aldehydes cinnamiques." Paris 6, 1994. http://www.theses.fr/1994PA066192.

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Des etudes electrochimiques anterieures ont montre que le mecanisme de polymerisation des alcools cinnamiques en lignine est de nature radical-radical dans l'eau et radical-anion dans l'acetonitrile. Dans ce memoire, nous avons etudie d'autres monolignols (principalement les aldehydes cinnamiques) qui sont impliques dans la biosynthese de la lignine dans le but de clarifier la nature des reactions qui interviennent dans le mecanisme de formation du biopolymere. Nous avons donc synthetise les trois aldehydes cinnamiques par une methode tres simple qui nous a permis d'avoir ces produits en grandes quantites. De meme, nous avons synthetise les trois alcools cinnamiques correspondants par simple reduction des aldehydes cinnamiques au borohydrure de sodium. Dans la seconde partie de cette these, nous avons essaye de determiner le mecanisme de polymerisation oxydante des trois aldehydes cinnamiques. Pour cela, nous avons utilise deux techniques complementaires: la voltametrie cyclique et la radiolyse pulsee qui nous ont montre que les radicaux phenoxy obtenus par oxydation des anions phenates subissent un couplage de type radical-radical aussi bien en milieu aqueux qu'en milieu aprotique. Des mesures cinetiques ont permis de mesurer les constantes de vitesse de ces dimerisations. L'ensemble de ces deux techniques a donc permis d'etablir de facon convaincante le mecanisme de dimerisation de ces aldehydes phenoliques. De plus, l'etude presentee apporte un certain nombre d'informations physico-chimiques tres interessantes concernant ces aldehydes: pk, potentiel redox, spectres des radicaux. Dans la derniere partie de cette these, nous avons decrit une synthese de divers produits marques destines a une etude biologique

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22

Sha, Li. "A synthetic approach to FR901483." Morgantown, W. Va. : [West Virginia University Libraries], 2001. http://etd.wvu.edu/templates/showETD.cfm?recnum=2103.

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Thesis (M.S.)--West Virginia University, 2001.
Title from document title page. Document formatted into pages; contains vii, 57 p. : ill. Includes abstract. Includes bibliographical references (p. 55-57).

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23

Waugh, Siobhan E. "The Kc-effect." Thesis, The University of Sydney, 2002. https://hdl.handle.net/2123/27905.

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This thesis examines an experimental and theoretical investigation into the dynamics of the reaction HZCO (v, J, K8, K) + hv -—> HCO (v, J, N, K3, K) + H (2H). Formaldehyde molecules were cooled in a supersonic free-jet expansion, dissociated with a laser and the ensuing formyl (HCO) fragments were probed by laser induced fluorescence spectroscopy. The initial experiments were carried out near the energetic threshold where very little energy is available to the product fragments. Subsequent experiments were carried out in three higher vibrational bands in the A( IAz) state. At these energies the dissociative surface is the formaldehyde ground state So, and the formyl and H fragments are formed in their ground electronic and vibrational states. Formaldehyde was prepared in numerous rotational states, characterised by J = 0 to 5, K8 = 0 to 3 and Kc = 0 to 5. The ensuing distribution of rotational energy in the HCO fragment was measured as a function of the N, K“, K and J = N i S quantum numbers of the fragment, and also the initial v, J, K“, Kr quantum numbers of the parent. The results found a dependence on both N and K2, in the fragment that could be modelled well using statistical analysis (phase space theory). This is consistent with statistical dynamics on a bound, barrierless surface. Within le cm‘1 of the energetic threshold, a centrifugal barrier affected the populations by inhibiting product states that require large orbital angular momentum. No dependence on the spin states, S = il/z, has been observed. The results also show a strong dependence on the quantum number, Kc, of both the parent and the product. When the Kc is resolved in both the parent and product, there are large deviations from the phase space theory model. We find that in the HCO K,l = l manifold there is always a preference (up to 5:1) for HCO to be produced in either the higher energy Kr state (NW—1) or the lower energy state (N1,N)- This preference is consistent over all N for any particular initial HZCO state, but may vary for different initial states. A correlation between this Kr preference and the initial state was observed: odd Kr formaldehyde states produce preferentially KC (lower) of HC0 and vice versa for initially even Kr states. A “Kr—effect” has been observed previously in the photodissociation of acetaldehyde and propionaldehyde to produce HCO. These experiments saw a strong preference for the upper energy component of the KC doublet, irrespective of the initial parent rotational state. The other system where Kc has been seen to play a role is the photodissociation of water. When H20 is photodissociated from a variety of rotational states with full KC resolution, different Kr states produced different A doublet states in the OH fragment. The similarities with these previous studies and the “Kc—effect” in formaldehyde are discussed and used as the starting point to develop a theory to explain the “Kr-effect” observations.

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Esiringu, Ilker. "Intermolecular Addition Of Aldehydes To Ketones Via Acyl Phosphonates." Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/3/12609441/index.pdf.

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This thesis presents a new developed method for first intermolecular aldehyde/ketone cross benzoin coupling. Protected &
#945
-keto tertiary alcohols are synthesized starting from easily available acyl phosphonates and ketones via Brook rearrangement in the presence of catalytic amount of cyanide ion. The scopes and the limitations of the methods for the synthesis of tertiary alcohols with &
#945
-keto group are discovered.

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25

Kaka, Naeem Shabbir. "Asymmetric synthesis of α-alkylated aldehydes using chiral enamines." Thesis, University of Oxford, 2008. http://ora.ox.ac.uk/objects/uuid:3a90d43d-8124-41ba-8ece-be714bdefee0.

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Direct generation of enantioenriched mono-α-alkylated aldehydes by intermolecular nucleophilic substitution is a general and long-standing problem in synthesis, and is of importance due to the diverse reactions such aldehydes undergo for introducing asymmetry into molecules. The work described in this thesis initially details the development of the first lithium amide capable of efficiently converting terminal epoxide into enamine functionality, where the latter also demonstrates effective C-alkylation activity. Not only addition to Michael acceptors, but more notably substitution using activated organohalides (α-bromoacetates, benzyl, allyl and propargyl bromide) gave the corresponding α-substituted aldehydes in good to excellent yields. Alkylation with propargyl bromide yielded only the propargyl-substituted aldehyde with none of the corresponding allene observed; this result shows that N-alkylation followed by [3,3] sigmatropic rearrangement is not occuring. Importantly, a range of short-, longer-chain and secondary unactivated alkyl iodides also proved viable. Significantly, with chiral lithium amides, the corresponding chiral enamines could be alkylated with strongly electrophilic benzyl, allyl and propargyl (no allene seen) bromides in very good yields, and with short chain alkyl iodides – MeI and EtI in satisfactory yields, to provide the first direct access to α-alkylated aldehydes with high asymmetric induction by intermolecular nucleophilic substitution.

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26

Cheeseman, Matthew D. "Temporary stereocentres for the asymmetric synthesis of chiral aldehydes." Thesis, University of Bath, 2005. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.426294.

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27

Delve, Robin. "Studies on cytotoxic aldehydes generated during lipid peroxidation in vivo." Thesis, University of Exeter, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.317350.

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28

Gomez-Lopez, J. "Selective hydrogenation of Î±-Î² unsaturated aldehydes over Ir catalysts." Thesis, Queen's University Belfast, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.403481.

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29

Kelly, Richard Victor. "Lanthanide complexes as catalysts for the enantioselective silylcyanation of aldehydes." Thesis, University of Liverpool, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.402261.

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30

Skaggs, Aaron J. (Aaron Jeremy) 1976. "Carbonyl ylide cycloadditions of dicobalt carbonyl complexes of propargylic aldehydes." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/17741.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 2004.
Vita.
Includes bibliographical references.
The intermolecular, three-component carbonyl ylide cycloaddition of a diazo compound, aldehyde, and carbon-carbon multiple bond is a powerful method to construct five-membered oxygen heterocycles. An adjacent dicobalt hexacarbonyl cluster permits the expansion of the scope of this process to include propargylic aldehydes (2-alkynals). The cluster not only increases the rate of reaction for this class of aldehydes, but also leads to a complete reversal in the diastereoselectivity compared to related methods and favors the exclusive formation of a 2,5- cis relationship in the products. Furthermore, the use of trimethylsilyldiazomethane (TMSD) as the carbene source allows coupling with a variety of dipolarophiles in moderate to high yields with good selectivity. Interaction of the (,il2-alkyne)Co2(CO)6 fragment with the neighboring positive charge of the 1,3-dipole is postulated to be a cause for the enhanced reactivity and selectivity. The choice of carbene transfer catalyst has no effect on either diastereocontrol or enantioselection, which suggests a mechanism involving a free ylide. While the Co2(CO)6 fragment can be removed to give the free alkyne in high, a catalytic amount of cobalt in the cycloaddition is modestly effective. Exchange of one or two carbonyls of the cobalt cluster by achiral and chiral phosphorous ligands results in dramatically lowered reaction efficiency. X-ray crystal structures of two of these substituted cobalt clusters are presented. -- [Image]
by Aaron J. Skaggs.
Ph.D.

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31

Dosa, Peter I. (Peter Ian) 1973. "Catalytic asymmetric addition of organozinc reagents to aldehydes and ketones." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/47412.

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McIntyre, Denise Lynne. "Novel linkers for the solid-phase synthesis of peptide aldehydes." Thesis, University of Edinburgh, 2004. http://hdl.handle.net/1842/11846.

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Serine and cysteine proteases are potently inhibited by peptide aldehydes. Compared with the plethora of methods available for solution synthesis of peptide aldehydes, there are relatively few methods for the solid phase synthesis of peptide aldehydes. The development of novel linkers for the solid phase synthesis of peptide aldehydes is reported (Scheme 1). When X = N, the aldehyde 4 can be cleaved in mild acid with 97% enantiomeric excess (e.e.). When X = O, base hydrolysis results in aldehyde 4 cleavage with complete epimerisation of the α-stereocentre. The use of Mucor meihei lipase and penicillin acylase generates the aldehyde 4 in 19 and 31% yield respectively, with complete retention of chiral integrity (>99%). The utility of linker 1 was demonstrated by the solid phase synthesis of a tetrapeptide aldehyde.

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33

Smith, Joshua J. "Stereoselective Rh- and Cu-catalysed additions to imines and aldehydes." Thesis, University of Nottingham, 2017. http://eprints.nottingham.ac.uk/39370/.

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Chapter 1.Copper-Catalysed Borylative Coupling of Vinylazaarenes and N-Boc Imines. Methodology for the copper-catalysed three-component couplings of vinylazaarenes, bis(pinacolato)diboron, and N-Boc imines has been developed. Oxidation of the initially formed boron species gives azaarene-containing, Boc-protected amino alcohols with reasonable to good diastereoselectivities. Additionally the synthetic utility of the reaction products have been demonstrated. The crude boron species have been shown to undergo a Suzuki-Miyaura cross coupling to give further functionalised products. Finally, facile deprotection of the reaction products is possible. Chapter 2. Chain Walking of Allylrhodium Species in Rhodium-Catalysed Nucleophilic Allylations of Imines and Aldehydes. Allylrhodium species derived from δ-trifluoroboryl β,γ-unsaturated esters undergo chain walking towards the ester moiety. The resulting allylrhodium species react with imines to give products containing two new stereocenters and a Z-alkene. By using a chiral diene ligand, products can be obtained with high enantioselectivities. A pronounced matched/mismatched effect with the chirality of the allyltrifluoroborate is also observed. In an analogous reaction a rhodium-hydride species has been shown to catalyse the addition of diene esters and aldehydes via allylrhodium intermediates which also undergo chain walking towards the ester moiety. The methodology enables allylation of aromatic aldehydes with compounds containing both diene and ester functionalities linked by carbon chains of up to eight carbons in length.

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34

Holmes, Jennifer Jane. "Metabolism and mechanisms of action of novel pyrazoloacridone and anthraquinone cytotoxic agents." Thesis, University of Strathclyde, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.249821.

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35

Annis, Alexandra H. "The Development of Rhodium-Catalyzed Asymmetric Hydroformylation of 1-Alkenes to Access Chiral Aldehydes." Thesis, Boston College, 2015. http://hdl.handle.net/2345/bc-ir:104636.

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Thesis advisor: James Morken
Asymmetric hydroformylation (AHF) is a metal-catalyzed reaction in which CO and H2 are added across an olefin to form a new carbon-carbon bond. AHF has perfect atom-economy and is an ideal way to form a chiral aldehyde. However, the utility of branch selective hydroformylation is limited due to a lack of readily available ligands and restrictions on a wide variety of terminal olefins. Herein, Rh-catalyzed asymmetric hydroformylation of 1-alkenes is reported using commercially available Ph-BPE ligand to generate α-chiral aldehydes. A wide range of terminal olefins were explored and all showed high enantioselectivity (up to 98:2 er) and good regioselectivity (up to 15:1 branched to linear ratio)
Thesis (MS) — Boston College, 2015
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Chemistry

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36

Langevin, Frédéric Paul Marcel. "The Fanconi anaemia DNA repair pathway counteracts the toxic effects of naturally produced aldehydes." Thesis, University of Cambridge, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.610334.

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37

Beddows, Claire J. "Aspects of the reactivity of coordinated ligands." Thesis, University of Bath, 1999. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.311456.

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38

Toh, Qiao Yan. "Organocatalysis in total synthesis and C-H bond arylation of aldehydes." Thesis, University of Cambridge, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.648134.

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39

Charlton, Andrew. "Towards the development of direct methodology to enantioenriched α-alkylated aldehydes." Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:bcfe43bb-1497-4f94-bcc7-6f7c2ae0b3a1.

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Enantiopure α-alkyl-substituted aldehydes are widely recognised as important building blocks in synthesis. Despite this, methods to prepare such substrates are limited. Strategically, asymmetric intermolecular S_N2 α-alkylation represents a highly straightforward transformation, but still remains an elusive feat. This thesis describes efforts to address this challenge, with attempted access to enantioenriched α-alkyl aldehydes by way of C-alkylation of chiral, non-racemic, hindered aldenamines using simple alkyl halides. Enamines derived from four types of auxiliary (a tropane, an oxazolidine, a pyrrolidine and a homotropane) have been prepared, and their alkylation profile examined. While the desired levels of asymmetric induction were not attained, use of the tropane and homotropane auxiliaries, which differ only by a single methylene group, interestingly, gave complimentary diastereocontrol during alkylation with EtI. The observed stereoselectivity is supported by density functional studies performed for ethylation of both enamines. Additionally, in the course of preparing the homotropane a highly efficient asymmetric synthesis of a homotropinone bearing gem-α-substitution has been developed.

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40

Khan, I. (Imran). "Role of aldehydes in biomass combustion and pulp and paper industry." Master's thesis, University of Oulu, 2014. http://urn.fi/URN:NBN:fi:oulu-201405281517.

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The purpose of this study was to investigate the role of aldehydes in two industrial sectors; biomass combustion and pulp and paper industry. Aldehydes are formed as unwanted intermediate compounds during biomass combustion, however in pulp and paper industry formaldehyde could be an important end product when treating the waste gas streams. Biomass fuels are the major renewable energy sources used in industries due to their environmental benefits. Emissions from biomass combustion depend on the composition of fuel and combustion conditions. In this work, emissions from the combustion of various solid biomass fuels in industrial scale boilers have been studied by a literature survey. It was observed that formaldehyde and acetaldehyde were the predominant intermediate compounds formed during biomass combustion. European Union directives 1999/30/EC and 2008/50/EC provide limiting values for the emissions from biomass boilers to protect human health. Aldehydes are unregulated pollutants that are toxic in nature and can cause adverse effects to human health and the environment. Black liquor is formed in pulp and paper industry during wood processing. Black liquor contains organic matter which can be used as an important biomass fuel in the recovery boiler. Pulping and bleaching processes of a pulp mill release hazardous compounds like methanol and methyl mercaptan. These compounds are commonly treated by incineration in a boiler. Incineration converts the waste stream to carbon dioxide and water thus increasing the greenhouse gases. Currently research is in progress to develop alternative ways for utilizing methanol containing waste gas streams, by converting them to other valuable compounds. In this regard catalytic oxidation has become a very promising technology. This is an environmentally friendly way to treat these emissions and in addition it has a positive economic impact on the pulp mill. This route is in experimental level and needs further research for its application in industrial scale. Formaldehyde is a very useful compound as it can be further utilized in a number of industries for the production of other compounds.

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41

Green, Robert Aaron. "Selective oxidations of alcohols and aldehydes in a microfluidic electrolysis cell." Thesis, University of Southampton, 2014. https://eprints.soton.ac.uk/366946/.

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Electrosynthesis uses electrical current to drive reactions as an alternative to stoichiometric reagents that may be toxic, expensive or create substantial waste. Despite the attraction, electrosynthesis has, however, never become routine procedure in the laboratory. The reasons for the apparent underuse are the perception that specialist knowledge and equipment is often required. The recent advances in microflow technology over the past decade have generated a number of electrosynthetic devices that address the perceived problems. Our own research into electrochemical microflow devices has led to the development of a now commercially available electrochemical flow cell. To fully advertise the benefits of electrochemical microflow technology synthetically useful reactions need to be developed. The optimisation of such reactions has been the focus of this Ph.D. research. The first reaction investigated was a selective electrochemical 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) mediated oxidation of alcohols to aldehydes and ketones. Cyclic voltammetry techniques were used to investigate the mechanism, and optimise the procedure, with 15 examples tested with excellent conversions and yields achieved in a single pass. We then turned our attention to the development of procedures for an electrochemical oxidative esterification and amidation mediated by N-heterocyclic carbenes (NHCs). The optimisation process was directed by a Design of Experiment (DoE) approach and supported by cyclic voltammetry (CV) experiments. 20 examples of esterification and 23 examples of amidation were demonstrated respectively in excellent yields in a single pass.

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42

Babić, K. "Extractant impregnated resins for the recovery of aldehydes and chiral resolution." Enschede : University of Twente [Host], 2009. http://doc.utwente.nl/61048.

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43

Jain, Pankaj. "Br[o/]nsted Acid Catalyzed Asymmetric Allylation and Propargylation of Aldehydes." Scholar Commons, 2014. https://scholarcommons.usf.edu/etd/5045.

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Carbonyl allylation and propargylation reactions have been an important tool for the stereocontrolled formation of carbon-carbon bonds for synthetic chemists. The chiral homoallylic and homopropargylic alcohols obtained from these reactions serve as versatile intermediates for the synthesis of natural and pharmaceutical products. Over the past three decades and continuing on, various synthetic groups around the globe have directed their research towards the efficient synthesis of these chiral moieties. In spite extensive research, asymmetric allylation and propargylation reactions remain an enduring challenge in organic chemistry. Chapter 1 of this thesis describes the first phosphoric acid catalyzed asymmetric allylboration of aldehydes. We found that the BINOL-derived phosphoric acids can efficiently catalyze the allylation reaction under specific conditions. Homoallylic alcohols were obtained in high yields and enantioselectivities from a wide variety of substrates. The optimized conditions were also found to be effective towards crotylboration of aldehydes. Chapter 2 describes the extension of the Br[o/]nsted acid catalyzed allylboration methodology to the propargylation of aldehydes. Homopropargylic alcohols were obtained with high selectivities with TRIP-PA as the catalyst. Synthesis of various important synthetic scaffolds from these chiral alcohols is also presented. The mechanistic insights studied by research groups of Kendall Houk and Jonathan Goodman have been outlined in chapter 3. These studies show that the major isomer is formed via a transition state involving the hydrogen bonding interaction between the hydroxyl group of the catalyst and the pseudoaxial oxygen of the boronate, with a stabilizing interaction of the phosphoryl oxygen to the formyl hydrogen. These insights helped us in developing new and highly efficient boronates that are described in the next chapter.

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Jagtap, Ravindra S. "Preparation of some organozinc compounds and their enantioselective addition to aldehydes." Thesis(Ph.D.), CSIR-National Chemical Laboratory, Pune, 2012. http://dspace.ncl.res.in:8080/xmlui/handle/20.500.12252/2123.

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45

Hoskins, Travis Justin Christopher. "Carbon-carbon bond forming reactions." Thesis, Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/29769.

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Thesis (M. S.)--Chemical Engineering, Georgia Institute of Technology, 2009.
Committee Chair: Dr. Christopher Jones; Committee Co-Chair: Dr. Pradeep Agrawal; Committee Member: Dr. Sujit Banerjee; Committee Member: Dr. Tom Fuller. Part of the SMARTech Electronic Thesis and Dissertation Collection.

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46

Wang, Hong. "Field and laboratory investigation of ozone-indoor surface reactions: secondary emissions inventory and implications for indoor air quality." Diss., Rolla, Mo. : University of Missouri-Rolla, 2007. http://scholarsmine.mst.edu/thesis/pdf/Wang_09007dcc8044137b.pdf.

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Thesis (Ph. D.)--University of Missouri--Rolla, 2007.
Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed February 6, 2008) Includes bibliographical references (p. 140-144).

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47

Oberbeck, Nina. "The role of intrauterine aldehyde catabolism in the pathogenesis of Fanconi anaemia." Thesis, University of Cambridge, 2015. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.708527.

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48

Wang, Junkuan. "Synthesis of aromatic aldehydes and the oscillatory behavior of their catalytic autoxidation /." [S.l.] : [s.n.], 1993. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=10371.

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49

Restorp, Per. "Stereoselective Nucleophilic Additions to α-Amino Aldehydes: Application to Natural Product Synthesis." Doctoral thesis, KTH, Organisk kemi, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4233.

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This thesis deals with the development and application of new synthetic methodology for stereo- or regioselective construction of carbon-carbon bonds in organic synthesis. The first part of this thesis describes the development of a divergent protocol for stereoselective synthesis of chiral aminodiols by employing Mukaiyama aldol additions to syn- and anti-α-amino-β-silyloxy aldehydes. The stereoselectivity of the nucleophilic attack is governed by either chelation to the α-amino moiety or by nucleophilic attack in the Felkin-Anh sense. This study is also directed towards the elucidation of the factors that dictate aldehyde π-facial selectivity in substrate-controlled nucleophilic additions to these and similar systems. In the second part, a highly stereoselective [3 + 2]-annulation reaction of N-Ts-α-amino aldehydes and 1,3-bis(silyl)propenes for stereoselective construction of densely functionalized pyrrolidines is presented. In addition, this methodology is also implemented as a keystep in a synthetic approach towards the polyhydroxylated pyrrolidine and pyrrolizidine alkaloids DGDP and (+)-alexine from a common late pyrrolidine intermediate. Finally, a divergent protocol for regioselective opening of vinyl epoxides using alkyne nucleophiles is described, in which the regioselectivity of the nucleophilic attack is controlled by the choice of reaction conditions. The regioselectivities of the SN2 and SN2’ processes are, however, significantly influenced by the nature of the alkyne substituents and the best results are obtained using ethoxyacetylene. The SN2 opening of vinyl epoxides with ethoxyacetylene as nucleophile is also shown to provide a straightforward entry to functionalized γ-butyrolactones.
QC 20100917

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50

Vaismaa, M. (Matti). "Development of benign synthesis of some terminal α-hydroxy ketones and aldehydes." Doctoral thesis, University of Oulu, 2009. http://urn.fi/urn:isbn:9789514291753.

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Abstract The synthesis of α-hydroxy aldehydes and hydroxymethyl ketones as well as their interconversion to each other are discussed in this thesis. The literature survey of the monograph reviews the synthetic methods for the preparation of 1,2-bifunctionalized hydroxy aldehydes and ketones. The keto-aldehyde isomerisation reaction catalyzed by Triosephosphate isomerase enzyme (TIM) and organic compounds that interact with the TIM are also introduced. In addition, the microwave heating techniques in organic syntheses are reviewed. The practical work consists of two entities: The synthesis of new substrate candidates and transition state analogues for a mutated monomeric TIM. These compounds are model compounds for the catalytic activity and the structural studies of the mutated monomeric TIM. The synthesis of the sulphonyl α-hydroxy ketone-based substrate candidates consists of four successive syntheses. The microwave-activation was utilized in the preparation of a carbon-sulphur bond and the synthesis of hydroxymethyl ketones. The improved synthesis of the terminal α-hydroxy ketone functionality with microwave activation is presented. The formation of charged compounds was utilized to improve the absorption of microwave energy of reaction mixtures. The design and the synthetic work were carried out in accordance to principles of green chemistry. The second part of the practical work is the development of an organocatalytic α-oxybenzoylation reaction of aldehydes with high enantiomeric selectivity. This novel method generated enantiomerically pure α-hydroxy aldehydes in the stable benzoate-protected form from achiral starting materials under mild conditions at the presence of air and moisture.

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Dissertations / Theses on the topic 'Aldehydes'

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