Patent ID: 7355043

Claim:
A process for the preparation of a compound of formula (A): wherein: X is hydrogen or hydroxy; and R a and R b are hydrogen or acetyl, which process comprises: (i) the preparation of a compound of formula (I): wherein R 1 is C 1-6 alkyl, or phenyl C 1-6 alkyl in which the phenyl group is optionally substituted; and R 3 is an amino group or a protected amino group, which preparation comprises the reaction of a compound of formula (II): wherein R 3 is as defined above for formula (I), with a compound of formula (V): wherein L is a leaving group and R 1 is as defined for formula (I), to give a compound of formula (VI): and thereafter converting the intermediate compound of formula (VI) to a compound of formula (I) via decarboxylation; and (ii) conversion of the resulting compound of formula (I) to a compound of formula (A) by: a) removal, if necessary, of the amino protecting group; b) reducing the ester groups CO 2 R 1 to CH 2 OH groups, and, if necessary, acetylating to form the corresponding CH 2 Oac groups; and c) dechlorinating via a hydrogenolysis reaction to yield a compound of Formula (A) in which X is hydrogen; or dechlorinating via a hydrolysis reaction to yield a compound of Formula (A) in which X is hydroxy.