Clay David R, Rosenberg Ashley G, McIntosh Matthias C
Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR 72701, USA.
Tetrahedron Asymmetry. 2011 Apr 10;22(7):713-716. doi: 10.1016/j.tetasy.2011.04.022.
Epoxy quinol 1a was prepared on a multi-gram scale by Noyori transfer hydrogenative desymmetrization of the readily available meso epoxy diketone 4. Although the intrinsic enantioselectivity for the desymmetrization was modest (82:18 er at 4% conversion), a highly enantiopure product (99.6:0.4 er) could be obtained in one operation in 44% yield via kinetic resolution of the minor enantiomer with long reaction times (48 h), or in 73% yield by combination with an enzymatic resolution of a 93:7 er mixture.
环氧喹诺酮1a是通过对易于获得的内消旋环氧二酮4进行野依转移氢化去对称化反应，以多克规模制备的。尽管去对称化反应的固有对映选择性一般（4%转化率时对映体比例为82:18），但通过延长反应时间（48小时）对次要对映体进行动力学拆分，一次操作即可获得高对映体纯度的产物（对映体比例为99.6:0.4），产率为44%；或者与对映体比例为93:7的混合物进行酶促拆分相结合，产率为73%。
