A versatile approach to 6-substituted-5-methoxy-δ-lactam framework and application to the formal synthesis of (±)-homopumiliotoxin 223G

Of the various 6-substituted-5-methoxy-δ-lactams were synthesized from α-sulfonyl acetamide in 4 steps in good yield. The key glutarimides were obtained via facile [3+3] annulation. The method featured regioselective introduction of C-6 substituents in glutarimides . Synthesis of tribenzyl lactam and the formal synthesis of (±)-homopumiliotoxin 223G were also reported.