Facile Synthesis of 1H,4H-cyclopenta[c]pyrrolo[1,2-b]isoquinolin-2(3H)-one

A novel and facile method for the synthesis of 4H-cyclopenta[c]pyrrolo[1,2-b] isoquinolin-2(3H)-one has been developed by employing the [2, 3] Stevens rearrangement of methyl N-allyl-N-benzylpyrrolidine 2-carboxylate to methyl 2-allyl-l-benzyl-pyrrolidine 2-carboxylate and acid-lactonisation as key transformations. The synthetic strategy from readily available materials provided a model skeletal analogue of cephalotaxine and should have general applicability in the synthesis of Cephalotaxus alkaloids.