Cheng Sen-Xiang, Chang Jun-Biao, Qu Ling-Bo, Chen Rong-Feng
Center of Research, Henan Academy of Science, Zhengzhou, Henan 450002, China.
Bioorg Med Chem Lett. 2004 Apr 5;14(7):1665-7. doi: 10.1016/j.bmcl.2004.01.054.
(R/S)-4,4'-Dimethoxy-5,6,5',6'-dimethenedioxy-2,2'-di-(4(S)-methyl-oxazoline-1)-biphenyl has been synthesized from dimethyl-4,4'-dimethoxy-5,6,5',6'-dimethenedioxy-biphenyl-2,2'-dicarboxylate, and then the diastereoisomer mixture was almost fully converted to a single diastereoisomer with S-configuration ((S)-3) through the key configuration transform promoted by CuI, which was confirmed by CD, HPLC and (13)C NMR. The C(2)-symmetric biphenyl, (S)-dimethyl-4,4'-dimethoxy-5,6,5',6'-dimethenedioxy-biphenyl-2,2'-dicarboxylate was prepared easily via the hydrolysis and ester exchange of (S)-3.
以4,4'-二甲氧基-5,6,5',6'-二甲烯二氧基-联苯-2,2'-二甲酸二甲酯合成了(R/S)-4,4'-二甲氧基-5,6,5',6'-二甲烯二氧基-2,2'-二-(4(S)-甲基-恶唑啉-1)-联苯，然后通过CuI促进的关键构型转化，将非对映异构体混合物几乎完全转化为具有S构型的单一非对映异构体((S)-3)，通过圆二色光谱(CD)、高效液相色谱(HPLC)和碳-13核磁共振(¹³C NMR)对其进行了确证。通过(S)-3的水解和酯交换反应轻松制备了C₂对称联苯(S)-4,4'-二甲氧基-5,6,5',6'-二甲烯二氧基-联苯-2,2'-二甲酸二甲酯。
