Synthesis of the putative structure of tridachiahydropyrone.

[reaction: see text] A short total synthesis of the putative structure of the marine natural product tridachiahydropyrone as a single enantiomer is described. Novel steps include a cuprate addition and cyclization to form a cyclohexanone ring and formation of the bicyclic pyrone with P(2)O(5) on Celite. The spectroscopic data obtained for compound 1 do not match those reported for tridachiahydropyrone; therefore, revision of the assigned natural product structure is warranted.