Selective lipase-catalyzed acylation of epimeric α-sulfinyl alcohols: an efficient method of separation
摘要:
A facile and efficient separation of mixtures of epimeric cc-sulfinyl alcohols 2:3 can be accomplished by selective lipase-catalyzed acylation with neat vinyl acetate. Pseudomonas cepacia and Candida rugosa lipase showed opposite epimer differentiation in the esterification. (C) 1999 Elsevier Science Ltd. All rights reserved.
Herstellung enantiomerenreiner Sulfoxide aus Milchsäure und 3-Hydroxybuttersäure: Isopropenyl-tolyl-sulfoxid und 2-(Phenylsulfinyl) acrylester
作者:Richard Breitschuh、Dieter Seebach
DOI:10.1055/s-1992-26328
日期:——
Preparation of Enantiomerically Pure Sulfoxides from Lactic Acid and 3- Hydroxybutyric Acid. Isopropenyl Tolyl Sulfoxide and 2-(Phenylsulfinyl) acrylate The EPC-synthesis of sulfoxides from readily available starting materials ("chiral pool") is demonstrated for the first time. Cyclic and open-chain thioethers derived from lactic and 3-hydroxybutyric acid are oxidized to sulfoxides, and the resulting products isolated in diastereomerically and enantiomerically pure form. Simple, large-scale conversions lead to methyl (S)-2-(phenylsulfinyl)acrylate and to (R)-isopropenyl tolyl sulfoxide from the corresponding (S)-lactate. Oxidation with tert-butyl hydroperoxide of chiral P-tolylthio-substituted propanols and butanols catalyzed by the addition of 1 % bis(2,4-pentadione)oxyvanadium(IV) (VOacac2) is diastereoselective (2:1 to 5.5: 1).
Humicola lanuginosa lipase-catalyzed acylation of beta -hydroxy sulfides provides both the (R)- and (S)-enantiomers in high enantiomeric purity. In two cases the resolved hydroxy sulfides were oxidized to give beta -hydroxy sulfoxides in > 99% e.e. The effect of substituents on enantioselectivity is discussed. (C) 2001 Elsevier Science Ltd. All rights reserved.
Diastereoselective oxidation of β-hydroxysulfides with TBHP: a comparative study of titanocenes and Ti(Oi-Pr)4 as catalysts
作者:Giorgio Della Sala、Stefania Labano、Alessandra Lattanzi、Arrigo Scettri
DOI:10.1016/s0040-4020(02)00686-5
日期:2002.8
Kita, Yasuyuki; Shibata, Norio; Yoshida, Naoki, Journal of the Chemical Society. Perkin transactions I, 1994, # 22, p. 3335 - 3342
A facile and efficient separation of mixtures of epimeric cc-sulfinyl alcohols 2:3 can be accomplished by selective lipase-catalyzed acylation with neat vinyl acetate. Pseudomonas cepacia and Candida rugosa lipase showed opposite epimer differentiation in the esterification. (C) 1999 Elsevier Science Ltd. All rights reserved.