Stereoselective 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 successive ether-ring formation reaction under acidic and basic conditions or one-pot double cyclization promoted by TBAF and stereoselective reduction of acyclic ketones adjacent to the 2,6-cis THP with Zn(BH4)2.