Patent ID: 7420078

Claim:
A process for the preparation of an intermediate compound of formula VI suitable for the preparation of statin derivatives, which comprises the reaction of the intermediate of formula I wherein X is halogen, acyloxy, activated hydrocarbyloxy, activated hydrocarbylthio or —N(CH 3 )—OCH 3 , R a is a hydroxy-protecting group and R b is a carboxy-protecting group, with chain lengthening, including the following reaction steps, as described below, wherein the intermediate of formula (I) reacts with an ethylene of formula II wherein Y a is halogen or hydrogen; there being obtained a keto compound of formula III wherein Y a is halogen or hydrogen, X a is halogen or acyloxy, R a is hydrogen, obtainable after removal of a hydroxy-protecting group R a , or a hydroxy-protecting group and R b is a carboxy-protecting group; the compound of formula III is reacted further in accordance with the following method (1), wherein a compound of formula III wherein Y a is hydrogen and X a is halogen, while R a and R b are as defined for compounds of formula III, is reacted with a salt of hydrazoic acid to form an azido compound of formula IV wherein R a is hydrogen or a hydroxy-protecting group and R b is a carboxy-protecting group, which compound, when R a is a hydroxy-protecting group, after prior removal thereof, is then reduced diastereoselectively to form a syn-diol compound of formula V wherein R a ′ is hydrogen and R c ′ is hydrogen; or, after subsequent introduction of protecting groups, R a ′ and R c ′ are each independently of the other hydrogen or a protecting group, with the proviso that at least one of the two radicals is a protecting group, or R a ′ and R c ′ together are a bridging hydroxy-protecting group; and R b is a carboxy-protecting group; and, in a case where the introduction of a bridging hydroxy-protecting group is desirable, if necessary, when R a ′ and R c ′ are each hydrogen, the bridging hydroxy-protecting group formed by R a ′ and R c ′ together being introduced using a suitable reagent; and the compound of formula V so obtainable is then reduced to the corresponding amino compound 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; wherein in the processes mentioned above, at any stage, even where not explicitly mentioned, if necessary one or more or all of the protecting groups present in the compounds of formulae I to VI are removed or one or more or all of the functional groups that are not to participate in a reaction, or that would interfere with the reaction, are converted into protected groups by the introduction of suitable protecting groups, and it being possible for the compounds of formulae I to VI, where salt-forming groups are present and the reaction in question is not impaired, also to be in salt form.