Patent ID: 7507843
Filing Date: 2009-03-24
Classification: C07D

Abstract:
1. A process for stereoselective synthesis of a compound of Formula X wherein: R R (a) reacting the starting material of formula A where X is Cl, Br, or I, with magnesium metal in a suitable solvent to prepare a Grignard intermediate of formula B (b) reacting the Grignard intermediate of formula B with a disubstituted oxalate of formula C, where R (c) hydrolyzing the compound of formula D in a suitable solvent to obtain the carboxylic acid of formula E (d) coupling the carboxylic acid of formula E with R*ZH, where R*ZH is a chiral auxiliary and R* is a chiral residue and Z is O or NH, in a suitable solvent to obtain a compound of formula F (e) reacting the compound of formula F with trifluoromethide ion source YCF (f) hydrolyzing the compound of formula G to remove the chiral auxiliary group R*ZH and obtain the compound of formula H (g) reducing the compound of formula H to obtain the compound of formula I (h) cyclizing the compound of formula I to obtain the epoxide compound of formula X