Synthesis of bis(bromomethyl) dimethyl crown ethers and complexation properties of their derivatives having electron-donating sidearms
作者:Yohji Nakatsuji、Tsuneharu Mori、Mitsuo Okahara
DOI:10.1016/s0040-4039(01)81190-4
日期:1984.1
Several bis(bromomethyl) dimethyl 15-crown-5, 18-crown-6, and 21-crown-7 were prepared according to two methods without protecting reactive bromo substituents. Cis and trans isomers of la are separated and the structures are inferred by considering the complexation property of their derivatives having electron-donating sidearms toward sodium and potassium cations.
(rac-1a) and 15-crown-5 diol (rac-1c) was achieved by lipase-catalyzed acetylation. The enantiomeric excess of the chiralcrown diols (95% ee and 82% ee) was determined by 1H NMR spectroscopy, using (R)-(+)-1-(1-naphthyl)ethylammonium hydrochloride as a shift reagent. The C2-symmetric chiral 15-crown-5 diol (>95% ee) was also obtained by kinetic resolution of the racemic diacetate (rac-2c) using lipase-catalyzed
C 2对称的18冠-6二醇(rac - 1a)和15冠5二醇(rac - 1c)外消旋混合物的动力学拆分通过脂肪酶催化的乙酰化作用实现。使用(R)-(+)-1-(1-萘基)乙基铵盐酸盐作为位移试剂,通过1 H NMR光谱法测定手性冠二醇的对映体过量(95%ee和82%ee)。通过使用脂肪酶催化的溶剂分解动力学拆分外消旋二乙酸酯(rac - 2c),也可以获得C 2对称的手性15冠-5二醇(> 95%ee)。