Syntheses of Showdomycin and its Anomer Using N-(Triisopropylsilyl)pyrrole as a Synthetic Equivalent for the Maleimide C3-Anion

Abstract

Showdomycin (1) and its anomer (2) have been prepared in four steps from readily available trichloroacetimidate 9.The key step involves reaction of the last compound with the title pyrrole 3 so as to form a chromatographically separable mixture of the pyrrole C-glycosides 10 and 11. Thesepyrroles are desilylated then oxidized to the corresponding maleimides using PCC.