ENZYMATIC ACYLATION USING ACID ANHYDRIDES: CRUCIAL REMOVAL OF ACID

Article abstract of DOI:10.1016/S0957-4166(00)80545-5

An efficient enzymatic resolution of 7,7-disubstituted 1,4,5,6-tetrachlorobicyclo<2.2.1>hept-5-en-2-ols was accomplished by means of lipase AY-30 from Candida cylindracea in toluene.When acid anhydrides were used as acyl donors, the enantioselectivity was found to depend strongly on the reaction conditions: Whereas low selectivity (E <20) was observed without precautions taken in order to remove the co-produced acid, a more than ten fold improvement was achieved with addition of a weak base (E >200).Alternatively, adsorption of the biocatalyst onto Celite was equally effective (E >300).Complete specificity was obtained when vinyl acetate was used as acyl donor (E ca.1000).