化学学报 ›› 1999, Vol. 57 ›› Issue (5): 527-532. 上一篇    下一篇

研究论文

雪松烷二醇硼酸酯的合成及其不对称同系化反应

宋一麟;范育波;丁宗彪;王全瑞;陶凤岗   

  1. 复旦大学化学系.上海(200433)
  • 发布日期:1999-05-15

Preparation and homologation of cedranediol boronic esters

Song Yilin;Fan Yubo;Ding Zongbiao;Wang Quanrui;Tao Fenggang   

  1. Fudan Univ, Dept Chem.Shanghai(200433)
  • Published:1999-05-15

报道了手性试剂雪松烷二醇硼酸酯(3)的合成及其和二氯甲基锂进行不对称同系化反应,生成α-氯代硼酸酯4R和4S,其R/S的比率在25:1以上,并且有手性助剂容易回收的特点。通过对同系化产物4cR的单晶X衍射分析,发现其分子中的1,3-二氧杂-2-硼杂环戊烷为非平面结构,文中就这一结构特点进行了初步讨论,解释了雪松烷二醇硼酸酯容易水解的原因。

关键词: 血松烷二醇硼酸酯, 不对称, 同系化, 手性试剂, X射线衍射分析, 二氯甲基锂, 氯代硼酸酯

(-)-Cedranediol boronic esters 3, a series of asymmetric homologation reagents were prepared from a new chiral director (-)- cedranediol 1 and boronic acids. 1 was easily synthesized by the dihydroxylation of (-)-α-cedrene 2 with OsO~4. Homologation of cedranediol boronic esters 3 with (dichloromethyl) lithium resulted in (R)-α-chloro boronic esters 4, with R/S-ratios over 25:1. It is easy to recover cedranediol for its boronic esters prone to rapid hydrolysis. The absolute configuration of cedranediol (R)-1-chloro-2- phenylethylboronate 4cR was determined by X-ray diffraction. The distortion of the five-membered 1, 3, 2-dioxaborolane ring of 4cR was found and discussed.

Key words: ASYMMETRY, HOMOLOGATION, CHIRAL REAGENT, X-RAY DIFFRACTION ANALYSIS

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