Abstract
Acospectoside A (1) and acovenoside B (2), two cytotoxic cardenolides extracted from the venomous South African bush Acokanthera oppositifolia, are distinguished by their unique structural motifs of the l-acovenose moiety at C-3 and a 1β-O-acetylated cardenolide aglycone. Here, we report the synthesis of these cardiac glycosides featuring delicate introductions of the 1-O-acetyl group under acid-catalyzed conditions, 14β-OH by Mukaiyama hydration, and a C17-butenolide moiety by Stille coupling.