Acetogenins of annonaceae. Part 86: synthesis of a highly functionalized precursor of (−)-4-deoxygigantecin, an annonaceous acetogenin

Abstract

A highly functionalized precursor of (−)-4-deoxygigantecin possessing six stereogenic centers has been prepared in 14 steps from tridecanal. The key steps are (i) enantioselective aldolization, (ii) diastereoselective C-glycosylation and (iii) diastereoselective aldolization reactions, all of them using 2-trimethylsilyloxyfuran as nucleophile. This strategy would allow us to prepare squamostatin D as well, another acetogenin of Annonaceae possessing two nonadjacent tetrahydrofuran rings and a closely related tetrahydrofuran pattern.