Inversion of enantioselectivity in quinine-mediated desymmetrization of glutaric meso-anhydrides

An unexpected inversion of enantioselectivity, dependent on the degree of quinine loading, was observed during the desymmetrization of glutaric meso-anhydrides. Decrease in catalyst loading from 1.6 equiv to 0.1 equiv caused a clear inversion of stereochemistry—from about 40% ee of (R)-configuration to about 40% ee of the opposite enantiomer. The effect of various carboxylic acid additives was also studied.

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