Chemoenzymatic synthesis of enantiomerically pure alkene 1,2-diols and glycosides thereof
作者:Thomas Ziegler、Frank Bien、Claus Jurisch
DOI:10.1016/s0957-4166(98)00051-2
日期:1998.3
The kinetic resolution of racemic 2-O-acylated 3-butene-1,2-diol and 1-O-acylated 3-butene-1,2-diol derivatives by enzymatic saponification and enzymatic esterification, respectively, is investigated with several lipases and esterases. The resulting partially blocked enantiomers are glycosylated with glycosyl halides and trichloroacetimidates, respectively. (C) 1998 Elsevier Science Ltd. All rights reserved.
Tandem Cycloaddition Chemistry of Nitroalkenes: Preparative and Theoretical Studies on the Stereochemical Course of [3 + 2] Cycloaddition of Cyclic Nitronates
作者:Scott E. Denmark、Mark Seierstad、B. Herbert
DOI:10.1021/jo9818374
日期:1999.2.1
Intermolecular [3 + 2] cycloadditions between two cyclic nitronates and a series of dipolarophiles are examined. High facial selectivity is observed in all cases and is analyzed with the aid of ab initio transition structure calculations. Monosubstituted dipolarophiles reacted with exclusive regiocontrol. Disubstituted dipolarophiles reacted with varying degrees of regiocontrol, which was dependent
Enzymatic preparation of enantiomerically pure and selectively protected 1,2- and 1,3-diols
作者:Ulrich Goergens、Manfred P. Schneider
DOI:10.1039/c39910001066
日期:——
The optically pure, selectively protected 1,2- and 1,3-diol derivatives (R)- and (S)-1–8 have been prepared by enzymatic hydrolysis of their racemic acetates and chloroacetates in the presence of ester hydrolase from Pseudomonas fluorescens(SAM-1).