ASYMMETRIC SYNTHESIS - PREPARATION OF CHIRAL METHYL CHIRAL LACTIC-ACID BY CATALYTIC ASYMMETRIC HYDROGENATION

Chiral methyl chiral lactic acid, a molecule which has a chiral methyl group because of the specific incorporation of the three isotopes of hydrogen, has been synthesized by a sequence of simple, convenient steps culminating in catalytic asymmetric hydrogenation. Moreover, the method allows for the preparation of all 12 possible isomers which arise from the permutation of the isotopes of hydrogen and of the two chiral centers. The absolute configuration of the chiral methyl group has been established. Chiral methyl chiral lactic acid is potentially a key molecule for biogenesis studies because numerous other specifically labeled substrates can be prepared from it by simple elaboration and degradation. © 1979, American Chemical Society. All rights reserved.