Synthesis of Cryptolepine and Cryptoteckieine from a Common Intermediate

Both cryptolepine 1 and cryptotackieine 3 have been synthesized from 1,3-bis(2-nitrophenyl)propan-2-one. The approach to 1 involved reduction of the NO2 groups, oxidative cyclization with PhI(OAc)2, and N-methylation, whereas 3 was obtained via bromination, Favorskii rearrangement, reduction (in situ cyclization), and N-methylation.