Patent ID: 7662610

Claim:
A process for the preparation of an acid of formula (I), as an individual (R) enantiomer or (S) enantiomer, or a salt thereof, wherein R is a protected amino group, and the asterisk * denotes a stereogenic carbon atom, wherein the process includes the steps of: (a) providing an ester of formula (II), as a mixture of (R) and (S) enantiomers, or a salt thereof, wherein R 1 is straight or branched C 1 -C 6 alkyl, optionally substituted with phenyl, and the asterisk * and R have the meanings defined above; and (b) contacting the ester of formula (II) with a lipase from Candida antarctica , under conditions effective to obtain a mixture comprising an acid of formula (I), as individual (R) enantiomer, and an ester of formula (II), as individual (S) enantiomer; wherein subsequent hydrolysis of the ester of formula (II) obtains an acid of formula (I), as individual (S) enantiomer.