Synthesis and stereochemical characterization of optically active 1,2-diarylethane-1,2-diols: Useful chiral controllers in the Ti-mediated enantioselective sulfoxidation
Synthesis and stereochemical characterization of optically active 1,2-diarylethane-1,2-diols: Useful chiral controllers in the Ti-mediated enantioselective sulfoxidation
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DOI：
10.1002/chir.1028
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发表时间：
2001-05-15
期刊：
影响因子：
2
通讯作者：
Rosini, C
中科院分区：
文献类型：
--
作者：
Donnoli, MI;Scafato, P;Rosini, C
通过相应的（E）-1，2-二芳基乙烯的Sharpless间二羟基化反应，以高的化学产率（70-80%）和光学产率（类似于90%）制备了一系列苯基取代的1，2-二苯基乙烷-1，2-二醇2a-h，所述（E）-1，2-二芳基乙烯依次通过McMurry或Wittig反应获得。样品的对映体过量通过使用Chiralcel OD手性固定相（CSP）的HPLC分析来测定。该CSP能够解析除2g之外的所有二醇，α值在1.10-1.64之间。在所有情况下，首先洗脱（R，R）对映体。通过对2，2-二甲基-1，3-二氧戊环3a-h的圆二色谱分析，确定了右旋（CHCl_3）二醇2a-h的（R，R）绝对构型。事实上，所有这些二氧戊环的CD光谱都呈现出正偶联体（210-180 nm范围），其可以与两个立构中心的（RR）绝对构型非经验相关。(C)2001 Wiley-Liss，Inc.
The series of phenylsubstituted 1,2-diphenylethane-1,2-diols 2a-h was prepared in high chemical (70-80%) and optical yields (similar to 90%) by Sharpless syndihydroxylation of the corresponding (E)-1,2-diarylethenes, in turn obtained by McMurry or Wittig reactions. The enantiomeric excesses of the samples were determined by HPLC analysis using Chiralcel OD chiral stationary phase (CSP). This CSP was able to resolve all the diols, except for 2g, with alpha values ranging between 1.10-1.64. In all cases the (R,R) antipode was eluted first. (R,R) absolute configuration was assigned to the dextrorotatory (CHCl3) diols 2a-h by analyzing the CD spectra of their 2,2-dimethyl-1,3-dioxolanes 3a-h. In fact, the CD spectra of all these dioxolanes present a positive couplet (210-180 nm range) which can be nonempirically related to an (RR) absolute configuration of the two stereocenters. (C) 2001 Wiley-Liss, Inc.