A novel and highly regioselective approach to 5-methoxy-6-substituted-3-sulfonyl-delta-enlactams from 5-methoxy-3-sulfonyl glutarimide: synthesis of cis-2-substituted-3-piperidinols.

A convenient method for the preparation of 5-methoxy-6-substituted-3-sulfonyl-delta-enlactams via regioselective nucleophilic addition to 5-methoxy-3-sulfonyl glutarimide is described. Formal syntheses of L-733,060, CP-99,994, and cassine are also reported.