Total synthesis of muconin

An antitumor acetogenin, muconin, was synthesized through a coupling reaction of a THF–THP segment and a terminal butenolide. The key reactions include 6-exo cyclization of an epoxy tetraol, regioselective cyclization of hydroxy tosylate, and stereoselective reduction of an acyclic ketone adjacent to the 2,6-cis THP ring with Zn(BH4)2.