Stereoselective Approach to the Racemic Oxatetracyclic Core of Platensimycin

A highly stereoselective synthesis of the racemic oxatetracyclic core of platensimycin has been accomplished from a known bicyclic epoxy lactone by an 11-step sequence that involves a Diels–Alder cyclcoaddition to construct its <i>cis</i>-decalenone structural motif with complete regio- and stereoselectivity and a ring-closing metathesis to establish its whole carbon framework.