Enzymatic procedures in the preparation of regioprotected D-fructose derivatives.

A combination of different lipases from Pseudomonas cepacia, Candida antarctica B, Candida rugosa and Mucor miehei, aided the regioesterification of the free fructose allowing the synthesis of 1,6-di-O-acetyl-D-fructofuranose, 1,4,6-tri-O-acetyl-D-fructofuranose, 1,6-di-O-acetyl-4-O-benzoyl-D-fructofuranose and 1,6-di-O-benzoyl-D-fructofuranose. Using C. antarctica B and C. rugosa lipases the alcoholysis of fructose peracetate (alpha, beta-form) has furnished 1,2,3,4-tetra-O-acetyl-alpha-D-fructofuranose and 2,3,4,6-tetra-O-acetyl-beta-D-fructofuranose. 1,4,6-Tri-O-acetyl-D-fructofuranose was successfully employed to produce a rare ketohexose, namely D-psicose.