Enantioselective synthesis of polyzonimine and nitropolyzonamine, spirocyclic compounds from the defensive glands of a millipede, Polyzonium rosalbum

Asymmetric Michael addition of the enamine derived from 2,2-dimethylcyclopentanecarboxaldehyde and (S)-prolinol methyl ether to nitroethylene afforded the adduct of 76% ee, which finally yielded enantiomerically pure (+)-polyzonimine and (+)-nitropolyzonamine, compounds from the defensive glands of a millipede, Polyzonium rosalbum. The absolute configuration of (+)-polyzonimine was determined as S.