申请人:DSM IP Assets B.V.
公开号:EP2213638A1
公开(公告)日:2010-08-04
The present invention relates to a method for the preparation of a compound of formula (I),
wherein R1 is different to R2; R3 is different to R4; and R1, R2, R3 and R4 are each a moiety other than hydrogen, which method comprises,
i) photoirradiating at an intensity above ambient intensity a solution comprising a compound of formula (II),
wherein R1, R2, R3 and R4 are as defined above, to form a solution of a mixture of compounds of formula (IIa) and (IIb),
wherein R1, R2, R3and R4 are as defined above; and
ii) contacting the mixture of compounds (IIa) and (IIb) with a hydrogen donating agent in the presence of an asymmetric hydrogenation catalyst, after initiation of i) and before termination of i).
本发明涉及一种制备化合物(I)的方法,其中R1不同于R2;R3不同于R4;且R1、R2、R3和R4各自是除氢之外的基团,该方法包括,i) 在高于环境强度的光照强度下光照含有化合物(II)的溶液,其中R1、R2、R3和R4如上定义,以形成化合物(IIa)和(IIb)的混合物的溶液,其中R1、R2、R3和R4如上定义;和ii) 在i)启动后且i)终止前,将化合物(IIa)和(IIb)的混合物与氢捐体在不对称氢化催化剂存在下接触。