Patent ID: 7612210

Claim:
A process for the stereoselective synthesis of a (4S or 4R)-4-benzy-3-[(2R or 2S)-(1-hydroxycyclohexyl)-(methoxyphenyl)acetyl]-1,3-oxazolidin-2-one having the structure wherein X is methoxy or trifluoromethoxy; comprising the steps of: treating a (4S or 4R)-4-benzyl-3-[(methoxyphenyl)acetyl]-1,3-oxazolidin-2-one having the structure wherein X is methoxy or trifluoromethoxy; with an aprotic amine base and titanium tetrachloride in a chlorinated solvent under conditions which permit formation of the corresponding anion; and mixing the corresponding anion with titanium tetrachloride and cyclohexanone under conditions which permit an aldol reaction to form said (4S or 4R)-4-benzyl-3-[(2R or 2S)-(1-hydroxycyclohexyl)-(methoxyphenyl)acetyl]-1,3-oxazolidin-2-one.