First total synthesis of glabramycin B and revision of its relative configuration

Abstract Structuralrevision of glabramycin B, which is an antibacterial 10-membered lactoneisolated from a fermentation broth of Neosartorya glabra , was achieved by enantioselective synthesisof our proposed structure. The correct structure of glabramycin B was presumed on comparison with related compounds, and synthesis of it was succeeded via dianion alkylation, Shiina's lactonizationand Stille cross-coupling. By this synthesis, we were able to correct the reported structural misassignment, and to confirm the relative configuration of glabramycin B to be 10 S *,11 S *,15 R *,20 S *.