A Five-Step Total Synthesis of Parvistone B.

The first total synthesis of a naturally occurring styryllactone secondary metabolite parvistone B has been achieved in five steps with an overall yield of 67 % from readily available trans-cinnamaldehyde. It exhibits cytotoxicity against different human tumour cell lines. Key features of our synthetic strategy include Maruoka asymmetric allylation, Sharpless epoxidation, ring-closing metathesis, and regioselective epoxide ring-opening. This synthetic strategy constitutes a step economical, atom economical and protecting group-free total synthesis.