Highly efficient double enantioselection by lipase-catalyzed transesterification of (R,S)-carboxylic acid vinyl esters with (RS)-1-phenylethanol
摘要:
Transesterification of the title compounds using lipase B from Candida antarctica in toluene afforded the corresponding esters in good to excellent diastereomeric excess. (R)-2-Phenylpropionic acid-(R)-1-phenethyl ester 4 was isolated in 45% yield and 64% de after 2.5 h, whereas (R)-2-phenylbutyric acid-(R)-1-phenethyl ester 5 was obtained in 40% yield and 56% de after 35 h. A single recrystallization from n-hexane gave 4 with 98% de. In all reactions CAL-B showed excellent enantioselectivity (E > 100) toward (RS)-1-phenylethanol and moderate enantioselectivity (E similar to 10) toward both carboxylic acid vinyl esters. (C) 1999 Elsevier Science Ltd. All rights reserved.
Determining the absolute configuration of hindered secondary alcohols - a modified horeau's method
作者:David E. Barnekow、John H. Cardellina
DOI:10.1016/s0040-4039(01)80466-4
日期:1989.1
The kinetic resolution of racemic 2-phenylbutyryl chloride by hindered chiral secondaryalcohols has been shown to be a viable approach to the determination of the absoluteconfiguration of secondaryalcohols through a study of ten chiral alcohols.
Probing the parallel kinetic resolution of 1-phenylethanol using quasi-enantiomeric oxazolidinone adducts
作者:Elliot Coulbeck、Jason Eames
DOI:10.1016/j.tetasy.2007.09.015
日期:2007.9
The parallel kinetic resolution of racemic 1-phenylethanol using an equimolar combination of quasi-enantiomeric oxazolidinones is discussed. The levels of diastereoselectivity were high leading to separable quasi-enantiomeric esters in good yield. (c) 2007 Elsevier Ltd. All rights reserved.
Parallel kinetic resolution of racemic 1-phenylethanol using quasi-enantiomeric combinations of carboxylic acids mediated by N,N′-dicyclohexylcarbodiimide and 3,5-lutidine
作者:Najla Al Shaye、Andrew N. Boa、Elliot Coulbeck、Jason Eames
DOI:10.1016/j.tetlet.2008.05.036
日期:2008.7
The parallel kinetic resolution of racemic 1-phenylethanol using an equimolar combination of quasienantiomeric 2-arylpropionic and butanoic acids mediated by a N,N'-dicyclohexylcarbodiimide (DCC)/3,5-lutidine coupling is discussed. The levels of diastereoselectivity were high leading to separable quasi-enantiomeric esters in good yield. (C) 2008 Elsevier Ltd. All rights reserved.