37505-07-0Relevant academic research and scientific papers
UTILISATION DES ALCOXYTRIALKYLALUMINATES EN SYNTHESE ASYMETRIQUE: SYNTHESE DE L'ACIDE HYDROXY-2, METHYL-2 BUTANOIQUE ENANTIOMERIQUEMENT ENRICHI EN R OU S
Vegh, D.,Boireau, G.,Henry-Basch, E.
, p. 127 - 132 (1984)
The reaction of LiAlEt3OR* with (-)-menthyl pyruvate (R*OH = (-)-N-methylephedrine) and with (+)-menthyl pyruvate (R*OH = (+)-N-methylephedrine) in hexane/ether as solvent produces the corresponding 2-hydroxy-2-methylbutan
Linum usitatissimum hydroxynitrile lyase cross-linked enzyme aggregates: A recyclable enantioselective catalyst
Cabirol, Fabien L.,Pei, Loo Tan,Tay, Benson,Cheng, Shiryn,Hanefeld, Ulf,Sheldon, Roger A.
experimental part, p. 2329 - 2338 (2009/10/23)
An immobilized form of the hydroxynitrile lyase from Linum usitatissimum (LuHNL) as cross-linked enzyme aggregate (CLEA) with high specific activity (303.5 U/g) and recovery (33%) was developed. Molecular imprinting using 2-butanone as additive in the immobilization process improved the synthetic activity of the biocatalyst. LuCLEA could be partially recycled for the synthesis of (R)-2-butanone cyanohydrin on a preparative scale over two batches. The enantioenriched cyanohydrin obtained was further hydrolyzed to give (R)-2-hydroxy-2-methylbutyric acid in 85% yield (from 2-butanone) and 87% ee.
Stereoselective biocatalytic synthesis of (S)-2-hydroxy-2-methylbutyric acid via substrate engineering by using "thio-disguised" precursors and oxynitrilase catalysis
Fechter, Martin H.,Gruber, Karl,Avi, Manuela,Skranc, Wolfgang,Schuster, Christian,Poechlauer, Peter,Klepp, Kurt O.,Griengl, Herfried
, p. 3369 - 3376 (2008/01/06)
3-Tetrahydrothiophenone (4) and 4-phenylthiobutan-2-one (7) were used as masked 2-butanone equivalents to give the corresponding cyanohydrins 5 (79% yield, 91% ee) and 8 (95% yield, 96% ee) in an enzymatic cyanohydrin reaction applying the hydroxynitrile
Process for the preparation of chiral α-hydroxycarboxylic acids
-
, (2008/06/13)
A process for the preparation of chiral α-hydroxycarboxylic acids: in which R1 is optionally halogen substituted C1-C2-alkyl and R2 is optionally halogen substituted C2-C3-alkyl from a compound: in which R′
Practical enantioselective synthesis of a COX-2 specific inhibitor
Tan, Lushi,Chen, Cheng-Yi,Chen, Weirong,Frey, Lisa,King, Anthony O,Tillyer, Richard D,Xu, Feng,Zhao, Dalian,Grabowski, Edward J.J,Reider, Paul J,O'Shea, Paul,Dagneau, Philippe,Wang, Xin
, p. 7403 - 7410 (2007/10/03)
Two synthetic strategies to the COX-2 specific inhibitor 1 have been described that allowed its preparation in large quantities in 79% overall yield from (S)-2-hydroxy-2-methylbutyric acid. These studies have led to the identification of an efficient resolution of (±)-2-hydroxy-2-methylbutyric acid and a novel thionyl chloride aided formation of amide 11 from acid 6.
Enzyme-catalyzed synthesis of (R)-ketone-cyanohydrins and their hydrolysis to (R)-α-hydroxy-α-methyl-carboxylic acids
Effenberger,Horsch,Weingart,Ziegler,Kuhner
, p. 2605 - 2608 (2007/10/02)
(R)-Ketone-cyanohydrins (R)-2 are obtained with high enantioselectivity from aliphatic ketones 1 and HCN in organic solvents using (R)-oxynitrilase ( EC 4.1.2.10) as catalyst. Acid catalyzed hydrolysis of the cyanohydrins (R)-2 affords the corresponding (R)-α-hydroxy-α-methyl-carboxylic acids (R)-3 without measurable racemization.
Functionalisation of Unsaturated Amides: Synthesis of Chiral α- or β-Hydroxy Acids
Cardillo, Giuliana,Hashem, Md. Abul,Tomasini, Claudia
, p. 1487 - 1488 (2007/10/02)
Mercury cyclisation of hemiamidals containing a stereogenic centre affords diastereoisomeric mixtures of tetrahydro-1,3-oxazin-4-ones or oxazolidin-4-ones, which are easily separated by silica gel chromatography and hydrolysed to give chiral α- and β-hydroxy acids.
Enzymatic Preparation of Enantiomerically Enriched Tertiary α-Benzyloxy Acid Esters. Application to the Synthesis of (S)-(-)-Frontalin
Sugai, Takeshi,Kakeya, Hideaki,Ohta, Hiromichi
, p. 4643 - 4647 (2007/10/02)
Enzymatic preparation of enantiomerically enriched tertiary α-benzyloxy acid esters is described.Enantioselective hydrolysis of the racemic esters of the formula by lipase OF (from Candida cylindracea, Meito Sangyo Co.) was succes
ELECTROPHILIC ASYMMETRIC SYNTHESES OF α-HYDROXY CARBOXYLIC ACIDS
Ludwig, Jerry W.,Newcomb, Martin,Bergbreiter, David E.
, p. 2731 - 2734 (2007/10/02)
Asymmetric electrophilic syntheses of α-hydroxy carboxylic acids from chiral amide derivatives of tert-butyl- and trialkylsilyl- protected glycolic and lactic acids are described which lead to chiral α-hydroxy carboxylic acids in 60-95percent diastereomeric excess.
