Synthesis of Aflatoxin B₂

Significance

Corey has previously described the use of oxazborolidinium catalysts for the asymmetric Diels-Alder reaction (D.-H. Ryu, G. Zhou, E. J. Corey Org. Lett. 2005, 7, 1633-1636 and references therein). The synthesis of the potent mutagen Aflatoxin B₂ features the first application of these catalysts to an asymmetric [3+2] cycloaddition reaction. For the only previous report of an asymmetric synthesis of Aflatoxin see: B. M. Trost, F. D. Toste J. Am. Chem. Soc. 2003, 125, 3090-3100.