Chiral bicyclic lactams as homoenolate equivalents: An asymmetric route to 5-substituted cyclohexenones

Article abstract of DOI:10.1016/S0040-4020(97)90391-4

Bicyclic Lactam 2 was transformed info α-cyanoenamine 8 in a four- step, high-yielding process. γ-Metalation of 8 was achieved using LiTMP in THF/HMPA, and the resultant homoenolate equivalent underwent stereoselective alkylation and subsequent hydrolysis to provide lactams of type 10 as a single diasteraomer. Partial reduction and hydrolysis of lactams 10 furnished enantiopure 5-substituted cyclohexenones 13 in good overall yield.