- An improved procedure for the synthesis of terminal and internal alkynes from 10-undecenoic acid
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A remarkable solvent preference for dehydrobromination to yield 10-Undecynoic acid (5) and 9-Undecynoic acid (6) is observed in the case of 10,11-dibromoundecanoic acid (1). Thus, 10-Undecenoic acid can be easily and quantitatively converted to 6 in PEG-400, while 5 is produced in PEG-200. 5 can also be obtained in non-polar solvents with PEG-200/400 as a phase transfer catalyst.
- Narasimhan,Mohan,Palani
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- Formation of gel and fibrous microstructures by 1-alkyne amphiphiles bearing L-serine headgroup in organic solvents
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The study of amphiphiles that form non-spheroidal, and other assemblies, upon solvation is the key to understanding the relationship between molecular structure and supramolecular morphology. With this aim in mind, we have employed L-serine and L-histidine derivatives that are linked via amide bond to hydrophobic chain. L-Serine amphiphiles form gels in CHCl3, CH2Cl2 and CCl4. Microscopic examinations of these gels reveal the coexistence of tubules, helical ribbons, and spheres. On the other hand, they produce only spherical structures and rods when dispersed in aqueous media (phosphate buffer). In contrast, amphiphiles based on the L-histidine group, neither formed any gel nor produced any microstructures in non-aqueous solvents like CHCl3, but produced spherical structures and helical rods in water. We also examined the effect of introducing 1-yne or 1-ene moieties into the hydrocarbon chain of such amphiphiles. These moieties, when present in the hydrophobic segment, do not perturb the supramolecular assembly features of the respective serine amphiphiles. Actually, 1-yne moiety, when present in the hydrophobic portion of the amphiphiles, gives characteristic UV-fine structures upon aggregation in water and might be used as a non-invasive marker for probing critical aggregate concentration.
- Ragunathan, Kaliappa G.,Bhattacharya, Santanu
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- Synthesis and functionalization of vinylsulfide and ketone-containing aliphatic copolyesters from fatty acids
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A series of novel aliphatic copolyesters bearing vinylsulfide and ketone functional groups were synthesized via lipase catalyzed polycondensation of vegetable oil derivatives. The vinylsulfide-containing hydroxyacid (VSHA) from 10-undecenoic fatty acid and the ketone-containing hydroxyester (KHE) from methyl oleate were used to obtain random copolymers and further sequential and single-step strategies involving the reactions with thiol and oxyamine were investigated. Good agreement between product and feed stoichiometries was achieved in both reactions for sequential modification, and the order of addition seems not to be a significant parameter. One pot functionalization allows for the single step modification, but not quantitative reactions were achieved.
- Beyazkilic, Zeynep,Lligadas, Gerard,Ronda, Juan Carlos,Galià, Marina,Cádiz, Virginia
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- Iron-Catalyzed Aerobic Oxidation of Alcohols: Lower Cost and Improved Selectivity
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An aerobic oxidation reaction of alcohols toward aldehydes or ketones using catalytic amounts of Fe(NO3)3·9H2O, 4-OH-TEMPO, and NaCl has been developed. Compared with the former catalytic system with TEMPO developed in this group, the new protocol using 4-OH-TEMPO, which is much cheaper on an industrial scale, accomplished the transformation with a higher selectivity, especially for aliphatic alcohols toward aldehydes. α,β-Unsaturated alkynals or alkynones can be efficiently synthesized from propargyl alcohols, which has been much less studied in the literature.
- Jiang, Xingguo,Liu, Jinxian,Ma, Shengming
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p. 825 - 835
(2019/05/02)
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- Iron-Catalyzed Aerobic Oxidation of Aldehydes: Single Component Catalyst and Mechanistic Studies
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An aerobic oxidation of aldehydes towards carboxylic acids in MeCN using 1 atm of pure oxygen or oxygen in air as the oxidant and a catalytic amount of single component catalyst, Fe(NO3)3·9H2O, has been developed. Carboxylic acids with different synthetically useful functional groups were obtained at room temperature. Two mechanistic pathways have been proposed based on isotopic labeling, NMR monitoring, and control experiments. The practicality of this reaction has been demonstrated by conducting several 50 mmol-scale reactions using pure oxygen or an air-flow of ~30 mL/min.
- Jiang, Xingguo,Zhai, Yizhan,Chen, Junyu,Han, Yulin,Yang, Zheng,Ma, Shengming
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supporting information
p. 15 - 19
(2017/11/23)
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- Configurational Assignment of ‘Cryptochiral’ 10-Hydroxystearic Acid Through an Asymmetric Catalytic Synthesis
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An asymmetric catalytic total synthesis of (S)-10-hydroxystearic acid (1) for comparison of its absolute configuration to that of samples obtained by fermentative hydration of oleic acid is reported. The synthesis involves two catalytic key-steps, namely Ru-catalyzed anti-Markovnikov hydration of 9-decynoic acid (7) to 10-oxodecanoic acid (5), followed by titanium-mediated asymmetric catalytic addition of dioctylzinc (25) to 5 in presence of the chiral ligand N,N’-((1R,2R)-cyclohexane-1,2-diyl)bis(1,1,1-trifluoromethanesulfonamide) (6). The synthesis is short and efficient and avoids use of protecting groups. Ozonolysis of 10-undecynoic acid (9) to 5 provides an alternative entry point into the synthetic route. The double dehydrobromination of (ω,ω-1)-dibromoalkanoic acids to ω-alkynoic acids under a variety of conditions was investigated with 10,11-dibromoundecanoic acid (11) as model substrate and using qNMR to quantify all reaction products. The synthetic approaches presented here have the potential to be generalized to the asymmetric catalytic synthesis of a variety of n-hydroxy-fatty acids.
- Brunner, Andreas,Hintermann, Lukas
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p. 928 - 943
(2016/12/09)
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- Enzyme kinetics and inhibition of histone acetyltransferase KAT8
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Lysine acetyltransferase 8 (KAT8) is a histone acetyltransferase (HAT) responsible for acetylating lysine 16 on histone H4 (H4K16) and plays a role in cell cycle progression as well as acetylation of the tumor suppressor protein p53. Further studies on its biological function and drug discovery initiatives will benefit from the development of small molecule inhibitors for this enzyme. As a first step towards this aim we investigated the enzyme kinetics of this bi-substrate enzyme. The kinetic experiments indicate a ping-pong mechanism in which the enzyme binds Ac-CoA first, followed by binding of the histone substrate. This mechanism is supported by affinity measurements of both substrates using isothermal titration calorimetry (ITC). Using this information, the KAT8 inhibition of a focused compound collection around the non-selective HAT inhibitor anacardic acid has been investigated. Kinetic studies with anacardic acid were performed, based on which a model for the catalytic activity of KAT8 and the inhibitory action of anacardic acid (AA) was proposed. This enabled the calculation of the inhibition constant Ki of anacardic acid derivatives using an adaptation of the Cheng-Prusoff equation. The results described in this study give insight into the catalytic mechanism of KAT8 and present the first well-characterized small-molecule inhibitors for this HAT.
- Wapenaar, Hannah,Van Der Wouden, Petra E.,Groves, Matthew R.,Rotili, Dante,Mai, Antonello,Dekker, Frank J.
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supporting information
p. 289 - 296
(2015/11/09)
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- HYDROXY FATTY ACID COMPOUNDS AND USES THEREOF FOR DISEASE TREATMENT AND DIAGNOSIS
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A compound of formula (I): wherein R represents a hydroxy substituted C24 - C40 straight chain aliphatic group containing at least one double bond in the carbon chain; and at least one carbon in the chain is substituted with a hydroxy group. Such compounds are useful for detecting inflammation, inflammatory disorders and cancer in a subject, and can also be used in therapeutic applications including treatment and/or prevention of these conditions. Pharmaceutical compositions, combinations and supplements, as well as methods of treatment using the described compounds are therefore also described.
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Page/Page column 64-65
(2011/02/24)
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- Synthesis of dodec-10E-Enyl acetate - The sex pheromone of phyllonorycter blancardella (Lepidoptera: Gracillariidae)
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Dodec-10E-enyl acetate has been synthesized from undecenoic acid. Field trials have shown its high attractiveness for Phyllonorycter blancardella males. 1996 Plenum Publishing Corporation.
- Ishchenko
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- Polyacetylenic lipids, radiation-sensitive compositions, photographic elements and processes relating to same
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A photopolymerizable monomer comprising a lipid having at least one hydrophobic acyl chain containing at least two conjugated acetylenic linkages is useful in preparing radiation-sensitive compositions and photographic elements comprising a plurality of liposomes. Further, processes for photopolymerizing the radiation-sensitive compositions and for forming an image in the photographic elements comprise exposing the lipid to radiation, heating the lipid to a temperature equal to or above a first transition temperature of the lipid to render it insensitive to further exposure, and optionally cooling the lipid to a temperature equal to or below a seocnd phase transition temperature of the lipid to render it again sensitive to further exposure. The monomeric lipids, when photopolymerized, form polymeric lipids exhibiting decreased solubility and liposome wall permeability as compared to the unpolymerized monomeric lipids.
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- Diacetylenic Liquid Crystalline Diesters
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Diesters of 10,12-docosadiyne-1,22-dionic acid with 4-hydroxy-4'methoxybiphenyl (I), 4-hydroxy-4'-methoxyazoxybenzene (II), and 4-hydroxy-4'-methoxy(2,2'-dimethyl) azoxybenzene have been prepared.The diester I displayed high sensitivity to light and u.v. irradiation while it was not mesomorphic.In contrants, diesters II and III were nematic while displaying considerably less radiation sensitivity.A suggested reason for this difference in behavior is the difference in the molecular packing of the corresponding crystal.The differnce in the mesomorphic behavior between II and III is explained in terms of mesogen broadening and distortion of the mesogen molecule of III by the methyl substituents.Keywords: diacethylenic diesters, synthesis of, liquid crystalline order
- Ozcayir, Y.,Blumstein, A.
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p. 237 - 246
(2007/10/02)
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- Diacetylenic Liquid Crystalline Polymers II: Derivatives of 10,12-Docosadiyne-1,22-Dioic Acid
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Polymers of 10,12-docosadiyne-1,22-dioic acid with different mesogenic groups have been prepared.The mesogenic groups were diphenyl (Polymer I); p-diphenylazoxy (Polymer II); 2,2'-dimethyldiphenylazoxy (Polymer III); 2-methyldiphenylazomethine (Polymer IV) and α-methylstilbene (Polymer V).All polymers crystallized extensively at room temperature, but only polymers I and V displayed an enantiotropic smectic mesophase.The X-ray diffractograms were consistent with a smectic H mesophase for both polymers.Polymers I and V differed also from polymers II-IV by enhanced reactivity of the diacetylenic moiety.A model for chain packing consistent with the X-ray diffraction pattern of the crystalline and the smectic phase is proposed.Keywords: diacetylenic polyesters, synthesis of, liquid crystalline order
- Ozcayir, Y.,Asrar, J.,Clough, S. B.,Blumstein, A.
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p. 167 - 178
(2007/10/02)
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- SIMPLE AND STEREOCONTROLLED SYNTHESIS OF AN OPTIMAL ISOMERIC MIXTURE OF 3,13-OCTADECADIEN-1-YL ACETATES
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A simple route has been developed for the preparation of the optimal isomeric mixture of 3,13-octadecadien-1-yl acetates (ODDA) which is the active sex pheromone of many Synanthedon species.The stereocontrolled formation of double bonds have been achieved via Wittig reaction and subsequent reduction of C-C triple bond.
- Vinczer, Peter,Baan, Gabor,Juvancz, Zoltan,Novak, Lajos,Szantay, Csaba
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p. 1257 - 1270
(2007/10/02)
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- Metamorphosis of Castor Oil to Insect Sex-pheromones and Useful Synthons
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The primary fragmentation products of Castor oil (1), namely, methyl undec-10-enoate (2) and sebacic acid (3) have been converted, using novel reactions and strategies into synthons of the type H-CC-(CH2)n-3-CH2OTHP (n=6=4; n=7=14; n=8=22; n=9=29).A surprisingly clean decarboxylative elimination of sebacic acid monoester gives methyl non-8-enoate (7), a synthon related to recefeiolide and a precursor to 4, the utility of which, has been illustrated with the synthesis of insect-pheromones of the species Grapholita molesta.Methyl dec-9-enoate (15) has been prepared by a novel and practical terminal ? to lower terminal ? degradation of 2.Compound 7 has been transformed via synthon 14 to the insect sex-pheromones of the species, Spodoptera frugiperda, Heliothis virescens and Paralobesia viteana in high yields and excellent stereochemical purity. 1-Tetrahydropyranyloxyundec-10-yne (22) readily prepared from 2, has been used to illustrate a new strategy in pheromone synthesis, namely, the use of coupling elements, leading to the preparation of bombykol in high yields and excellent stereochemical purity. 1-Tetrahydropyranyloxydodec-11-yne (29), already reported, has been transformed to vaccenic acid (30), the transposed ?-isomer of oleic acid, in good yields, thus demonstrating the use of acetylide synthons for the preparation of rare fatty acids also.
- Ranganathan, S.,Maniktala, Vibha,Kumar, Raaj,Singh, G. P.
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p. 1197 - 1207
(2007/10/02)
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