Kinetic resolution of racemic halohydrins, precursors of optically active di- and trialkyl-substituted epoxides, with lipase from Pseudomonas sp.
摘要:
Asymmetric acetylation of racemic halohydrins with vinyl acetate catalyzed by lipase from Pseudomonas sp. afforded the optically active beta-halo alcohols 1 and acetates 2 in high enantiomeric excess (68 to > 98%). The enzymatic kinetic resolution was performed on the preparative scale and the halo alcohols 1 and acetates 2 led to the optically active epoxides 3 after base treatment. (C) 1997 Elsevier Science Ltd.
Regio- and stereoselective hydroxybromination and dibromination of olefins using ammonium bromide and oxone®
作者:Arun Kumar Macharla、Rohitha Chozhiyath Nappunni、Narender Nama
DOI:10.1016/j.tetlet.2012.01.026
日期:2012.3
synthesis of vicinal bromohydrins and dibromides fromolefins is presented. Various olefins are regio- and stereoselectively hydroxybrominated and dibrominated with anti fashion, following Markonikov’s rule, using eco-friendly, non-toxic, and stable reagents such as NH4Br and oxone® in CH3CN/H2O (1:1) and CH3CN without employing catalyst in moderate to excellent yields. Bromohydrins are formed instantaneously
Chemoenzymatic synthesis of “α-bichiral” synthons. Application to the preparation of chiral epoxides
作者:Pascale Besse、Henri Veschambre
DOI:10.1016/s0957-4166(00)80239-6
日期:1993.6
Microbiological reduction of 3-bromo-2-octanone and 3-azido-2-octanone led to all the stereoisomers of 3-bromo-2-octanol and 3-azido-2-octanol. Chiral 2,3-epoxyoctanes were prepared from the 3-bromo-2-octanols.