An efficient strategy for the synthesis of polysubstituted chromeno[4,3-b]pyrrolidine derivatives.

A powerful cascade reaction was developed for the synthesis of chromeno[4,3-b]pyrrolidines with high yields and excellent stereoselectivities. This efficient cascade reaction expeditiously established two fused rings which bear three contiguous stereogenic centers including one quaternary stereocenter in a single operation with low catalyst loading under mild conditions.