Enzymatic synthesis of 2,3-O-isopropylidene-sn-glycerol, a chiral building block for platelet-activating factor.

Abstract

An enzymatic synthesis of 2, 3-O-isopropylidene-sn-glycerol (10), the synthetic key intermediate for platelet-activating factor, was achieved. Several 1, 3-di-O-acyl-2-benzylglycerols (5a-d) were synthesized from dihydroxyacetone dimer (2), and subjected to enzyme-catalyzed asymmetric hydrolysis. The optical purities of the mono-hydrolyzed products (6) were determined from the 400 MHz proton nuclear magnetic resonance spectra after conversion of 6 to the esters of (-)α-methoxy-α-trifluoromethylphenylacetic acid. Upon hydrogenolysis of the benzyl ether, followed by protection of diol and hydrolysis of the acetate, (-)-6a afforded 10.