Highly stereoselective synthesis of vicinal diols by stannous chloride-mediated addition of hydroxyallylic stannanes to aldehydes
作者:Makoto Yasuda、Tatsuya Azuma、Kensuke Tsuruwa、Srinivasarao Arulananda Babu、Akio Baba
DOI:10.1016/j.tetlet.2009.01.137
日期:2009.7
A new protocol for the synthesis of vicinal diols was accomplished by the reaction of unprotected α-hydroxymethylmetals, as hydroxymethyl anion equivalents, with aldehydes. The treatment of hydroxyallylic stannanes, which were prepared from α,β-unsaturated aldehydes and Bu3SnLi in situ, with various aldehydes gave but-3-en-1,2-diols in the presence of SnCl2. The stereochemistry of the diol and olefin
通过未保护的α-羟甲基金属(如羟甲基阴离子当量)与醛的反应,完成了邻位二醇合成的新方案。由α,β-不饱和醛和Bu 3 SnLi原位制备的羟基锡烷与各种醛的处理在SnCl 2存在的情况下可生成3-en-1,2-二醇。二醇和烯烃部分的立体化学分别显示出顺-和E-选择性。我们提出以下反应机制;SnCl 2对羟基烯丙基锡进行金属重金属化产生重排的烯丙基锡(II)物种,该物种通过环状过渡态进行醛加成反应。未保护的羟基部分与锡(II)中心之间的严格相互作用说明了选择性。