Enantioselective acetalization of racemic 1,3-alkanediols with l-methone under kinetically controlled conditions
作者:Toshiro Harada、Sachi Tanaka、Akira Oku
DOI:10.1016/s0040-4020(01)89438-2
日期:——
(derived from 1) in preference to spiroacetal 4 (derived from ent-1). The kinetically controlled acetalization is applied to a novel kinetic resolution of racemic 1,3-alkanediols: Optically active diols ent-1 of 55–95 % ee are obtained when the racemic diols are allowed to react with 1.5 equiv of enol silyl ether 10 under similar conditions.
外消旋的1,3-链烷二醇(rac -1)通过在三氟甲磺酸(10 mol%)存在下用1-甲基烯醇三甲基甲硅烷基醚(10)处理进行对映选择性缩醛化反应,从而得到热力学上较不稳定的螺缩醛3(由1衍生)。优先于螺乙缩醛4(源自ent -1)。动力学控制缩醛化被施加到外消旋的1,3-链烷二醇的新颖动力学拆分:光学活性二醇ENT -1 55-95%ee值时的外消旋二醇使其与烯醇甲硅烷基醚1.5当量反应得到10 在相似的条件下。