A facile and practical method of preparing optically active α-monosubstituted cycloalkanones by thermodynamically controlled deracemization
作者:Hiroto Kaku、Aya Nakamaru、Makoto Inai、Takeshi Nishii、Mitsuyo Horikawa、Tetsuto Tsunoda
DOI:10.1016/j.tet.2010.09.085
日期:2010.11
efficiency of this thermodynamically controlled deracemization was strongly influenced by the mixture ratio of the solvent, H2O/MeOH. Based on this finding, an improved method of preparing (R)-2-monosubstituted cycloalkanones with higher optical purity was developed. For example, (R)-2-(4-methylbenzyl)cyclohexanone (5) was obtained in 85% yield with 98% ee, when a 1:1 mixture of H2O/MeOH was used as the solvent
当在碱性MeOH水溶液中将TADDOLs(例如1a,b)用作主体分子时,外消旋的2-单取代的环烷酮被转化为R-异构体。该热力学控制的脱硝的效率受到溶剂H 2 O / MeOH的混合比的强烈影响。基于该发现,开发了制备具有更高光学纯度的(R)-2-单取代的环烷酮的改进方法。例如,(- [R)-2-(4-甲基苄基)环己酮(5以85%的产率得到98%ee的,当1):H 1混合物2中使用O / MeOH作为溶剂中的存在1a。