雪松二醇-(R)-1氯-1-苯基甲基硼酸酯(phCHClBO_2C_(15)H_(24))的不对称合成和晶体结构

Asymmetric Synthesis and Structure of Cedranediol (R)-1-Chloro-1-Phenylmetylboronate

利用雪松二醇苯基硼酸酯进行不对称合成反应，制得标题化合物并测定结构．其晶体属正交晶系，空间群为P212121。结晶学多数为：a=5．728（3），b=8.543（3），c=41．267（7）A，V=2019．7A3；Z=4，Dc=1．23g／cm3，μ（CuKa）=17.7cm－1，R=0．0072，Rw=20．0077．独立可观察反射点数（I＞3σ（I））为739个。由晶体结构图可看出，由于雪松二醇基团的空间住阻效应，反应产物有很高的非对称选择性。

Asymmetric synthesis of cedranediol phenyle boronic ester, phBO2C15H24, with (dichloromethyl) lithium has yielded to Cedranediol (R ) - 1 - Chloro- 1 - Phenylmetylboronate, phCHClBo2C15H24. The crystal structure of the complex belongs to orthorhombic system with spacegroup P212121 and cell parameters: a=5. 728(3), b=8. 543(3), c= 41. 267(7) A, V= 2019. 7A3 ; Z=4, Dcal= 1. 23g/cm3, μ(CuKa) = 17. 7cm-1, R=0.0072, Rw=0.0077.The result of crystal structure analyses shows that the product of asymmetric synthesis hashigh diastereomeric purity owing to the steric hinderance effect of cedranediol group.