P. Virsu et al., Preparation of the enantiomers of 1-phenylethan-1,2-diol. Regio- and enantioselectivity of acylase I and Candida antarctica lipases A and B, TETRAHEDR-A, 12(17), 2001, pp. 2447-2455
Acylase 1 and Cundida antarctica lipases A (CAL-A) and B (CAL-B) were evalu
ated for the preparation of the enantiomers of 1-phenylethan-1,2-diol. In t
he presence of CAL-B, the sequential one-pot methanolysis of the diacetate
in acetonitrile allowed the preparation of (S)-diol (e.e. 97%) and (R)-1-ac
etoxy-1-phenylethanol (e.e. 94%). Base-catalyzed methanolysis of the monoac
etate resulted in the corresponding (R)-diol. When one of the diol enantiom
ers wets subjected to Mitsunobu esterification, inversion of configuration
occurred, allowing transformation of the initially racemic mixture to one e
nantiomer. Acylase 1-catalysis led to the chemo- and enantioselective forma
tion of (S)-1-acetoxy-1-phenylethanol (e.e. 97%) in the presence of the pri
mary hydroxyl function through acetylation of the secondary hydroxyl group.
The low chemical yield (ca. 25%) was due to the moderate enzymatic regiose
lectivity. CAL-A behaved in a similar way to acylase 1. (C) 2001 Elsevier S
cience Ltd. All rights reserved.