Kinetic resolution of 2-acylated-1,2-diols by lipase-catalyzed enantiomer selective acylation
摘要:
Enantiomer selectivity of lipase catalyzed acylation of 2-acylated 1,2-diols was studied. First, acylation of 2-acetoxyheptan-1-ol rac-3b with vinyl acetate was investigated by varying the enzyme and the solvent, showing the highest enantiomer selectivity by using lipase from Pseudomonas fluorescens (PfL) in hexane-vinyl acetate (VA). We have found varying or even reversed enantiomer selectivity for different secondary acyl moieties in 2-acyloxyheptan-1-ols rac-3bA-F. Next, all six possible types of enantiomer selective biotransformations (hydrolysis of diacetate and the two kinds of monoacetetes; acylation of diol and the two kinds of monoacetates) were compared on two model diols rac-4b,d. Among the transformations investigated, acetylation of secondary monoacetates rac-3b,d showed the highest enantiomer selectivity. Finally, PfL catalyzed acetylations of several 2-acetylated 1,2-diols rac-3a-g were investigated under our optimum conditions. Copyright (C) 1996 Elsevier Science Ltd
Benzyl chloromethyl ether reacts with carbonylcompounds in the presence of SmI2 to afford alcohols (I), which are subsequently subjected to hydrogenolysis to yield diols (II).
Abstract Reaction of the protected glycidol derivatives (1A-C) with a wide variety of Grignard reagents (2a-h) in the presence of catalyticamount of CuCN provided the corresponding monoprotected diol derivatives (3) in a highly regioselective manner.
Optically active compounds, their preparation and their use in liquid crystal compositions and liquid crystal optical modulators
申请人:HITACHI, LTD.
公开号:EP0322862A2
公开(公告)日:1989-07-05
The invention relates to optically active compounds represented by the general formula I
wherein n, R1, R2, R3, R4., Q1, Q2, Q3, and M are defined as in the specification, methods and intermediates for their preparation, liquid crystal compositions comprising at least one optically active compound of formula I and their use in electrooptical display, switching and modulation devices.
本发明涉及通式 I 所代表的光学活性化合物,其中 n、R1、R2、R3、R4.
其中 n、R1、R2、R3、R4.、Q1、Q2、Q3 和 M 的定义如说明书中所述,还涉及制备它们的方法和中间体、包含至少一种式 I 的光学活性化合物的液晶组合物以及它们在光电显示、开关和调制装置中的用途。
Imamoto, Tsuneo; Hatajima, Toshihiko; Takiyama, Nobuyuki, Journal of the Chemical Society. Perkin transactions I, 1991, # 12, p. 3127 - 3135
[EN] PYRIDIN-3-YL ACETIC ACID DERIVATIVES AS INHIBITORS OF HUMAN IMMUNODEFICIENCY VIRUS REPLICATION<br/>[FR] DÉRIVÉS D'ACIDE PYRIDIN-3-YL-ACÉTIQUE EN TANT QU'INHIBITEURS DE LA RÉPLICATION DU VIRUS DE L'IMMUNODÉFICIENCE HUMAINE