CHEMOENZYMIC PRODUCTION OF LACTAMS FROM ALIPHATIC ALPHA,OMEGA-DINITRILES

Five- and six-membered ring lactams have been prepared by first conver ting an aliphatic alpha,omega-dinitrile to an omega-cyanocarboxylic ac id ammonium salt, using a microbial cell catalyst having an aliphatic nitrilase activity (Acidovorax: facilis 72W, ATCC 55746) or a combinat ion of nitrile hydratase and amidase activities (Comamonas testosteron i 5-MGAM-4D, ATCC 55744). The omega-cyanocarboxylic acid ammonium salt was then directly converted to the corresponding lactam by hydrogenat ion in aqueous solution, without isolation of the intermediate omega-c yanocarboxylic acid or omega-aminocarboxylic acid. Only one of two pos sible lactam products was produced from alpha-alkyl-substituted alpha, omega-dinitriles, where the nitrilase of A. facilis 72W regioselective ly hydrolyzed only the omega-cyano group to produce a single cyanocarb oxylic acid ammonium salt in greater than 98% yield.