Construction of the Bicyclic Carbon Framework of Euphosalicin.

Our studies toward the total synthesis of the natural product euphosalicin ( 1 ) are presented. Different approaches targeting key intermediates are described, the synthesis of which includes findings on asymmetric dihydroxylations and ring-closing enyne metatheses (RCEYM). Their connection allowed the isolation of highly advanced precursors for studies on macrocyclizations. Our efforts culminated in the preparation of the unique C11/C12 ( Z ) isomer of the C13 nor methyl skeleton of euphosalicin ( 1 ).