A SYNTHESIS OF SALINOMYCIN .2. SYNTHESIS OF THE DISPIROACETAL CORE UNIT VIA OXIDATIVE REARRANGEMENT OF AN ACYL FURAN

A synthesis of the polyether antibiotic Salinomycin is completed by th e union of the C11-C20 furan fragment 2, the C21-C30 lactone fragment 3 , and the C1-C9 tetrahydropyran fragment 14. A key step in the seque nce is the oxidative rearrangement of a 2-acyl furan to the 1,6,8-trio xadispiro[4. 1.5,3]pentadec-13-ene core unit.