Asymmetric Total Synthesis of Pseurotin A

The asymmetric total syntheses of pseurotin A and 8-O-demethylpseurotin A have been accomplished. Key reactions are a NaH-promoted intramolecular cyclization of an alkynylamide to form a gamma-lactam, an aldol reaction of a benzylidene-substituted ketone, and the late-stage introduction of the benzoyl group by a selective oxidation of a benzylidene moiety with dimethyldioxirane (DMD). [reaction: see text]