Abstract

Diacetoxy SO2-uracil analog diacyclonucleosides have been deprotected via Lipase-mediated alcoholysis. The reactivity and regioselectivity of the reaction are dependent on the steric hindrance of distant 5-substituents, even if they are as small as a methyl or a 4,5-trimethylene chain, and, in a lesser extent, the electronic or hydrogen bond interactions of 3-carbonyl and hydroxyl-chain groups. (C) 1998 Elsevier Science B.V. All rights reserved.