Asymmetric total synthesis of botcinic acid and its derivatives: synthetic revision of the structure of botcinolides

The stereoselective total syntheses of botcinic acid, botcinic acid methyl ester, 3-O-acetylbotcinic acid methyl ester, botcineric acid, and botcinin E were achieved. The structures of these compounds have been unequivocally determined through their total synthesis, and they are identified with the revised structures of botcinolide, 4-O-methylbotcinolide, 3-O-acetyl-5-O-methylbotcinolide, homobotcinolide, and 2-epibotcinolide, respectively.