Formal total synthesis of altohyrtin C (spongistantin 2). Part 2: Construction of full elaborated ABCD and EF fragments

摘要

Coupling of the C1-C14 (AB) crotylstannane with the C15-C28 (CD) aldehyde followed by stereochemical arrangements gave the C1-C28 (ABCD) fragment of altohyrtin C. The C29-C44 (EF) fragment was also prepared. The syntheses of these two fragments, both of which were identical with those prepared by the Smith group, constitute a formal total synthesis of altohyrtin C.