Activation of n-3 polyunsaturated fatty acids as oxime esters: a novel approach for their exclusive incorporation into the primary alcoholic positions of the glycerol moiety by lipase.

A novel approach has been developed for activating the highly bioactive long-chain n-3 polyunsaturated fatty acids EPA and DHA as oxime esters and incorporating them exclusively to the end-positions of glycerol and enantiopure 1-O-alkylglycerols. The Candida antarctica lipase B was observed to display a superb regioselectivity when using the acetoxime esters of EPA and DHA as acyldonors under mild condition to keep acyl-migration side-reaction under complete control. Regiopure 1,3-diacylglycerols, 1-O-alkyl-3-acyl-sn-glycerols and their antipodes possessing EPA and DHA were afforded in very high purity and yields.