Asymmetric Synthesis of (<i>S</i>,<i>S</i>)- and (<i>R</i>,<i>R</i>)-2-Methylthreitol
作者:Dieter Enders、Evelyn Peiffer、Gerhard Raabe
DOI:10.1055/s-2007-965967
日期:2007.4
The asymmetric synthesis of ( S, S)- and ( R, R)-2-methylthreitol was carried out, starting from the SAMP or RAMP hydrazone of 2,2-dimethyl-1,3-dioxan-5-one. The protocol involves an enantioselective α-alkylation as a key step. The second stereogenic center was installed by either nucleophilic 1,2-addition or diastereo-selective epoxidation with bis(acetylacetonato)oxovanadium(IV) [VO(acac) 2 ] as
(S,S)-和(R,R)-2-甲基苏糖醇的不对称合成是从2,2-二甲基-1,3-dioxan-5-one的SAMP或RAMP腙开始进行的。该协议涉及对映选择性α-烷基化作为关键步骤。第二个立体中心是通过亲核 1,2-加成或非对映选择性环氧化以双(乙酰丙酮)氧钒 (IV) [VO(acac) 2 ] 作为催化剂安装的。以优异的非对映体和对映体过量(≥98% de,98% ee)和良好的总产率(40-61%)获得了标题化合物。