Synthesis of chromeno[4,3-b]pyrrolidines from azomethine ylides and vinyl para-quinone methides via (3?+?2) cycloaddition/oxa-1,6-addition

An efficient synthesis of chromeno[4,3-b]pyrrolidines has been successfully developed. This strategy involves a base-catalyzed reaction of p-VQMs and o-hydroxy azomethine ylides via (3 + 2) cycloaddition/oxa-1,6-addition reaction sequence. The reaction condition is mild, and a series of chromeno[4,3-b]pyrrolidines were obtained in 49-95% yields with excellent diastereoselectivity (dr > 20:1).

Automated summary

An efficient synthesis of chromeno[4,3-b]pyrrolidines has been developed via a mild base-catalyzed reaction, achieving excellent diastereoselectivity.