DIASTEREOSELECTIVITY IN THE ALKYLATIONS OF BICYCLIC PIPERIDINONES

The synthesis of substituted [4.3.0] bicyclic lactams derived from 6-o xo-2-hydroxymethylpiperidine is described. The enolate derived from th ese systems can be alkylated with a range of reactive electrophiles; t he diastereoselectivity which can be achieved depends on the substitut ion pattern of the oxazolidine ring system and the nature of the alkyl ating reagent, and can vary from 1:1 to as much as 10:1. (C) 1998 Else vier Science Ltd. All rights reserved.