Asymmetric Synthesis of (+)-Tanikolide and the ß-Methyl-Substituted Analogues of (+)-Tanikolide and (-)-Malyngolide

The d-lactone-containing natural product (+)-tanikolide, a brine shrimp toxin and antifungal compound, was synthesized in nine steps with an overall yield of 26.4?% by employing Sharpless asymmetric epoxidation and ZrCl4-catalyzed intramolecular acetalization as the key steps. The novel beta-methyl-substituted analogues of (+)-tanikolide and()-malyngolide have also been prepared by using the same asymmetric synthetic approach.