Diisopropyl tartrate modified (E)-γ-[(cyclohexyloxy)dimethylsilyl]- and (E)-γ-(dimethylphenylsilyl)allylboronates: Chiral Reagents for the Enantio- and Diastereoselective synthesis of anti 1,2-diols and 2-butene-1,4-diols via the formal α- and γ-hydroxyallylation of aldehydes
作者:William R. Roush、Paul T. Grover
DOI:10.1016/s0040-4020(01)88869-4
日期:1992.1
Enantioselective synthesis of 4-substituted (E)-2-butene-1,4-diols and anti 1,2-diols are described. Highly diastereoselective reactions of aldehydes and the chiral PhMe2Si- and (C6H11O)Me2Si- substituted allylboronates 25 and 26 provide anti homoallylic 29 and 50, respectively. Epoxidation of 29 with dimethyl dioxirane followed by acid catalyzed Petersen rearrangement of the intermediate epoxysilanols
描述了4-取代的(E)-2-丁烯-1,4-二醇和抗1,2-二醇的对映选择性合成。醛与手性PhMe 2 Si-和(C 6 H 11 O)Me 2 Si-取代的烯丙基硼酸酯25和26的高度非对映选择性反应分别提供反均聚物29和50。29用二甲基二环氧乙烷环氧化,然后经酸催化的中间体环氧硅烷醇进行Petersen重排,可得到具有优异对映选择性(81-87%ee)的1,4-丁二醇27。Tamao氧化50提供抗二醇22(ee的64–72%)。这些程序尤其在与一系列氧化的手性醛进行双不对称反应时获得了优异的结果(图1和2)。这些方法有望用于非环状前体糖的非对映选择性合成中。