(+)-Rimocidin synthetic studies: construction of the C(1-27) aglycone skeleton

Assembly of the C(1-27) macrocyclic skeleton of rimocidinolide, the aglycone of (+)-rimocidin (1), has been achieved in convergent fashion. Key features of the synthetic strategy entail application of multicomponent Type I Anion Relay Chemistry (ARC), in conjunction with the S(N)2/S(N)2' reaction manifolds of vinyl epoxides, both employing 2-substituted 1,3-dithianes to construct the C(1-19) carbon backbone. Yamaguchi union of a C(20-27) vinyl borate ester, possessing the all-trans triene, with an advanced C(1-19) vinyl iodide followed by macrocyclization via Suzuki-Miyaura cross-coupling completed construction of the C(1-27) rimocidinolide skeleton.