Patent ID: 8569520

Claim:
A process for preparing a compound represented by Formula (I): wherein n is 0, m is an integer selected from 0 and 1; R 2 is selected from C 1-4 alkyl; which comprises: Step a): treating a compound of Formula (II): wherein X 1 and X 2 are independently selected from a bromine atom or an iodine atom; P 1 is a metal ion, a hydrogen atom or a protecting group of hydroxy; and n is as defined above; with an organometal reagent, and then reacting with a compound of Formula (III): wherein P 2 , P 3 , P 4 , and P 5 are independently selected from a protecting group of hydroxy; or P 2 and P 3 , P 3 and P 4 , and P 4 and P 5 together may independently represent a divalent group to protect two hydroxy groups and to form a ring; to obtain a compound represented by Formula (IVa): wherein n, X 2 , P 1 , P 2 , P 3 , P 4 , Y and P 5 are as defined above; and X is a metal ion, or a hydrogen atom; Step b): treating a compound represented by Formula (IVb): wherein n, X 2 , P 1 , P 2 , P 3 , P 4 , and P 5 are as defined above; and P 6 is a metal ion, a hydrogen atom or a protecting group of hydroxy; with an organometal reagent, and then reacting with a compound represented by Formula (V): wherein R 42 is a group defined as R 2 and m is as defined above; and which may further comprise one or more steps to introduce a protecting group and/or to remove a protecting group, in the steps defined above and/or in any stage prior to or after any one of the steps defined above.