Total synthesis of (-)-lycoperine A.

Lycoperine A was synthesized through a highly convergent route in which a double alkylation of 2,6-dicyano-N-benzylpiperidine with the octahydroquinoline moiety gave the lycoperine skeleton. The octahydroquinoline was prepared by a desymmetrization reaction of 5-methylcyclohexane-1,3-dione. Hydrolysis, reductive amination, and cyclization gave lycoperine A in 13 steps and 3% overall yield. The absolute configuration of lycoperine A was assigned as 6R,6'R,8R,8'R,13S,17R.