Patent ID: 7317123
Filing Date: 2008-01-08
Classification: C07C,C12P,Y02P

Abstract:
1. A process for the preparation of the intermediate of formula VI wherein R a ′ and R c ′ are each independently of the other hydrogen or a hydroxy-protecting group or together are a bridging hydroxy-protecting group, and R b ′ is a carboxy-protecting group, which is suitable for the preparation of statin derivatives, comprising: (i) reducing the carbonyl at the carbon adjacent the terminal nitrogen; and (ii) removing the amide-protecting groups from the intermediate of formula XVI wherein R a ′ and R c ′ are each independently of the other hydrogen or a hydroxy-protecting group, R* and R** are each independently of the other hydrogen or an amide-protecting group, and R b ′ is a carboxy-protecting group; wherein the compound of formula XVI is prepared by a process comprising: (a) preparing a compound of formula I wherein X is halogen, acyloxy, activated hydrocarbyloxy, activated hydrocarbylthio or —N(CH 3 )—OCH 3 , R a is hydrogen or a hydroxy-protecting group and R b is a carboxy-protecting group, (b) substituting an amine group for X in the compound of formula I; (c) removing R (d) regioselectively substituting OR using a compound of formula XX in the presence of a strong base, wherein R b ′ is a carboxy-protecting group, to form a compound of formula XV; (e) diastereoselectively reducing compound XV; wherein the compound of formula I is prepared by converting a compound of formula XI wherein R a is a hydroxy-protecting group and R b is a carboxy-protecting group, into the corresponding compound of formula I using a reagent that introduces the radical X.