An easy preparation of opticallyactive 1,2-diol monotosylate derivatives by enzymatic hydrolysis is disclosed. Lipase PS ( BURKHOLDERIA CEPACIA) catalyzes the hydrolysis of racemic 2-acetoxyhexyl tosylate with excellent enantioselectivity to afford the corresponding opticallyactive compounds. In this reaction, a unique temperature effect is observed. After optimizing the reaction conditions, this
Deracemization of 1,2-diol monotosylate derivatives by a combination of enzymatic hydrolysis with the Mitsunobu inversion using polymer-bound triphenylphosphine
The deracemization of 1,2-diol monotosylate derivatives is achieved by the sequential combination of enzymatic hydrolysis and Mitsunobu inversion using a polymer-bound triphenylphosphine. After the lipase-catalysed hydrolysis of the racemic 2-acetoxyhexyl tosylate, the subsequent Mitsunobu reaction without separation causes an inversion of the resulting (R)-alcohol to give the (S)-enantiomer of the acetate as a single product. In particular, the reaction using the polymer-bound triphenylphosphine also proceeds smoothly, and the product is easily separated by filtration from the polymer-bound reagent and its by-products. This deracemization process is applicable to the preparation of several optically active 1,2-diol monotosylates. (C) 2009 Elsevier Ltd. All rights reserved.
CHEN, CHING-SHIH;LIU, YEUK-CHUEN, TETRAHEDRON LETT., 30,(1989) N1, C. 7165-7168