Convergent synthesis of the ABCDEF-ring system of yessotoxin and adriatoxin.

[formula: see text] The convergent synthesis of the ABCDEF-ring system of yessotoxin and adriatoxin was accomplished. This efficient convergent strategy was performed on the basis of the coupling of the acetylide of the A-ring and the triflate of the DEF-ring, oxidation of the alkyne to diketone, intramolecular diacetalization, and stereoselective reduction of the diacetal with Et3SiH-TMSOTf.