A CHEMOENZYMATIC APPROACH TO OPTICALLY-ACTIVE 3-(4-METHOXYCARBONYL)PHENYL-2-METHYL-1-PROPANOLS

With a view to obtaining both enantiomers of 3-(4-methoxycarbonyl)phen yl-2-methyl-1-propanols, (R)-1 and (S)-1, from the respective racemate , (+/-)-1, the hydrolysis of its acetate, (+/-)-2, in the presence of porcine pancreatic lipase (PPL) has been studied. The optical puriry o f (R)-1 and (S)-1 thus obtained was unsatisfactory (ee 22-27 %), and c ould not be increased beyond ee 33 % by repeated enzymatic hydrolysis of the unconverted fraction of the acetate. In contrast with this, the biohydrogenation of 3-(4-methoxycarbonyl)phenyl-2-methyl-2-propen-1-o l (4) with fermenting Saccharomyces cerevisiae afforded (S)-1 of consi derably higher optical purity (ee 41-90 %, depending on the strain). T he stereochemical correlation of the products obtained in the two bioc hemical processes under study shows that the PPL-catalyzed hydrolysis of (+/-)-2 produces preferably (R)-1.