Stereoselective reduction of menthone by molecularly imprinted polymers

Polymeric chiral reductants selective for the reduction of (−)-menthone 1 to the diastereomeric products (−)-menthol 2 and (+)-neomenthol 3 were prepared by a covalent molecular imprinting using 2 as the template. The LiAlH4 derivatized imprinted polymers altered the natural outcome of the reduction reaction (LiAlH4) from 2:1 [(−)-menthol:(+)-neomenthol] to 1:1. The reaction mechanism is discussed in terms of reaction site structure. The molecularly imprinted polymers demonstrated enantioselective recognition for 2 (0.15 μmol enantioselective sites/g polymer) in batch binding experiments.