Abstract: Eight aromatic methyl ketones have been reduced by sodium borohydride in the presence of optically active quaternary ammonium salts as phase tranfer catalyst in CH₂C1₂-H₂O system, and optically active alcohols have been obtained.
One of the optically active quaternary ammonium salts which have been synthesized is a new compound.
By using methoxy menthol as optically active solvent the optical purities of the reduced products are raised apparently.
It is for the first time in the literature to introduce this chiral medium into this reduction system.