ENZYME-CATALYZED HYDROLYZES OF E Z-DIASTEREOTOPIC AND E/Z-DIASTEREOMERIC ESTERS - AFFECT ON SELECTIVITY BY REACTION MEDIA/

PLE-catalyzed hydrolyses of different types of E/Z-diastereotopic dies ters and E/Z-diastereomeric monoesters have been studied. Arylidenepro panedioic diesters are specifically hydrolyzed to the Z-half esters, w hereas the de values for dialkylated methylene propanedioic diesters r ange between 33 and 79% (Z). D values for the hydrolyses of the 3-meth yleneazetidin-2-ones in detergent-buffer systems depend on the size of the substituent in the alpha-position. Diastereoselectivity of these substrates is affected by addition of the cosolvents acetonitrile and methanol.