Enzymatic resolution of 2-aryloxy-1-propanols via lipase-catalyzed enantioselective acylation using acid anhydrides as acyl donors

Pseudomonas sp. lipase-catalyzed enantioselective acylation procedure using acid anhydrides as acyl donors was exploited for the resolution of 2-aryloxy-1-propanols carrying different substituents on the benzene ring. These primary alcohols, which belong to primary alcohols with an oxygen atom at the stereocenter, were resolved generally with moderate to good enantioselectivity (E of up to 55) through the acylation with hexanoic anhydride in diisopropyl ether at 25 °C in a short reaction time. With the alcohol substrate, which gave a low enantioselectivity in the acylation at ordinary temperature, the selectivity proved to be enhanced by conducting the reaction at low temperature (−10 °C). By this acylation procedure employing the acid anhydride, enantiomerically pure (R)-2-phenoxy-1-propanol was prepared in a gram-scale reaction.