The (R,R)-diastereoisomer of oxazolidin-2-ones, which are chemical intermediates for the preparation therapeutic agents useful in the treatment of diabetes and hyperglycemia, are prepared substantially free of isomeric forms through reduction of an acid addition salt of an (R)-N-protected-N-phenylcarboxymethyl-1-phenylprop-2-ylamine to form a secondary alcohol of predominantly the (R,R) chiral form in preference to others, removal of the protecting group to form a secondary amine, and allowing the secondary amine to react with a source of carbonyl groups. A typical embodiment involves the preparation of (R,R)-3-[1-(3,4-dimethoxyphenyl)prop-2-yl]-5-(3-chlorophenyl)oxazolidin-2- one in which both the chemical purity and optical purity are in excess of 99%.
(R, R)-
二噁烷基-2-酮的立体异构体是制备治疗糖尿病和高血糖有用的药物的
化学中间体,通过还原(R)-N-保护-N-苯甲酰甲基-1-苯基丙-2-胺的酸加成盐,形成主要为(R,R)手性形式的二级醇,去除保护基形成二级胺,然后让二级胺与羰基源反应,从而实现基本无异构体形式的制备。一个典型的实施例涉及制备(R,R)-3-[1-(3,4-二
甲氧基苯基)丙-2-基]-5-(3-
氯苯基)
二噁烷-2-酮,其中
化学纯度和光学纯度均超过99%。