Indium- and Zinc-Mediated Acyloxyallylation of Protected and Unprotected Aldotetroses—Revealing a Pronounced Diastereodivergence and a Fundamental Difference in the Performance of the Mediating Metal
作者:Markus Draskovits、Christian Stanetty、Ian R. Baxendale、Marko D. Mihovilovic
DOI:10.1021/acs.joc.7b03063
日期:2018.3.2
were successfully applied to the indium and also zinc-mediated acyloxyallylation, with the latter being a first for an unprotected sugar. The investigation largely benefited from the choice of these more exotic starting materials as it allowed unambiguous identification/quantification of the hexose-products which are available as authentic reference materials. The observed diastereoselectivities indicate
十多年前,未经保护的醛糖的酰氧基化首次被证实为还原糖的潜在的优雅的二碳同系物(通过臭氧分解)。但是,它在实际案例合成中的应用仍然很少。在如此成功的展示之后,我们回答了有关这一有吸引力的转变的几个悬而未决的问题,我们进行了深入的方法学重新调查。将未受保护和受保护形式的差向异构体四聚体l-赤藓糖和d-苏糖成功应用于铟以及锌介导的酰氧基烯丙基化,后者是未保护糖的首创。该研究很大程度上得益于这些更具异国情调的起始原料的选择,因为它可以对己糖产品进行明确的鉴定/定量,而后者可作为可靠的参考材料。观察到的非对映选择性表明对底物有很强的控制作用(O2处的立体化学),并详细研究了试剂结构对选择性的影响。相关保护和未保护结构之间存在强烈的面部非对映差异,并且铟和锌之间的性能表现出乎意料的显着差异。