Process for preparing a single enantiomer of a lactam using lactamase

Claim 1

A process for preparing a single enantiomer, substantially free of other enantiomers, of a lactam of the formula ##STR5## wherein X is --CH 2 --, --(CH 2 ) 2 --, --CH 2 --Q-- --Q--CH 2 - and Q is a heteroatom (including NH); either Y and Z are independently selected from --CH 2 -- and a heteroatom (including NH) or --Y--Z-- is --CH═CH--, --CH═CH--, --CH═CH--; and R n is absent or represents one or more independently-selected substituents which do not interfere with the lacatamase reaction at any available position(s) on the X,Y,Z-containing ring; said process comprising the steps of: (a) reacting a mixture of enantiomers of the lactam of formula I with either (1) [an enzyme having lactamase activity] a lactamase capable of stereoselective cleavage of one of said enantiomers, or (2) a microorganism [having said lactamase activity] which produces said lactamase, thereby forming a mixture of said single enantiomer of the lactam of formula I and an enantiomer, having the opposite stereochemical configuration, of the formula ##STR6## wherein X, Y, Z and R n are as defined above; R 1 is H or alkyl; and R 2 is H or a N-blocking group; (b) isolating said single enantiomer of said lactam of formula I, and optionally isolating said enantiomer of opposite configuration of formula II.