Efforts towards the total synthesis of (+)-sorangicin A

Efforts towards (+)-sorangicin A, a previously unprepared antibiotic macrolide, are reported. A modular approach which investigates several coupling strategies for the union of three core cyclic ether fragments was utilized. The bicyclic ether and tetrahydropyran moieties were constructed utilizing a ringclosing/epoxide opening strategy while the dihydropyran subunit relied on a ring-closing metathesis for the formation of the heterocycle. The three core synthetic fragments were elaborated to various synthetic intermediates and several coupling strategies were evaluated