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). 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.