Patent ID: 8669362

Claim:
A process for the preparation of a compound of formula (I): wherein R is —CHO, -or —CH(OH)(OR 4 ); P 1 is H or a hydroxyl protecting group; P 3 is H or a carboxy protecting group; R 3 is H, halogen, hydroxy, optionally substituted lower alkyl, optionally substituted cycloalkyl, optionally substituted lower alkenyl, optionally substituted lower alkoxy, optionally substituted lower alkenyloxy, optionally substituted aryl, optionally substituted aryloxy, optionally substituted heterocyclic group, optionally substituted heterocycleoxy or optionally substituted amino; R 4 is lower alkyl; R x is H, halo or R 2 —X—NR 1 —C(O)—; R 2 is optionally substituted aryl; X is a single bond, a heteroatom group selected from O, S, SO, SO 2 , and NH or loweralkylene or lower alkenylene wherein each may be intervened by the heteroatom; and R 1 is H or lower alkyl, which comprises the steps of: i) reacting a compound of formula (II): with an amine of formula (III) or (IV): wherein R 5 and R 6 are independently lower alkyl or R 5 and R 6 can be alkyl and joined to form a 5-, 6-, or 7-membered ring, to produce an intermediate of formula (V) or (VI), respectively: and ii) refunctionalizing (V) or (VI) to produce (I).