Combined synthetic/CD strategy for the stereochemical assignment of the tricarballylic acid side chains of fumonisin B(1).

The circular dichroism (CD) exciton chirality method was employed for the stereochemical assignment of the tricarballylic acid (TCA) side chains of fumonisin B(1) 1a (FB(1)). Using 2-naphthoate for chromophoric derivatization of the reduced TCA moieties, the absolute configuration was shown to be R. For additional confirmation, an optically active dihydroxy-tert-butanoate 2 related to the TCA group of fumonisin B(1) was synthesized to serve as a model compound.