Total synthesis of three eudesman-12,8-olides, (±)-isoalantolactone, (±)-dihydrocallitrisin and (±)-septuplinolide; structure revision of septuplinolide

Abstract

Four eudesman-12,8-olides, (±)-isoalantolactone, (±)-dihydrocallitrisin, (±)-septuplinolide and its epimeric eudesmanolide at C-4 were synthesized stereoselectively via the route involving alkylation annulation of 2-methyl-3-furoic acid and oxidation of the furan ring. It was found that the structure of septuplinolide is the C-4 epimer of the reported structure.