Total synthesis of scytophycin C. 1. Stereoselective syntheses of the C(1)-C(18) segment and the C(19)-C(31) segment

Stereoselective total synthesis of scytophycin C, a marine 22-membered macrolide displaying potent activity against a variety of human carcinoma cell lines, has been reported in which the polypropionate structure bearing contiguous asymmetric centers was stereospecifically constructed by using new acyclic stereocontrol. This paper describes stereoselective syntheses of the C(l)-C(18) segment (Segment A) including a trans-disubstituted dihydropyran ring and the C(19)-C(31) segment (Segment 13) having eight stereogenic centers.