作者:Pravin C. Patil、Frederick A. Luzzio、Donald R. Demuth
DOI:10.1016/j.tetlet.2014.11.014
日期:2015.6
New routes to 2, 4, 5-trisubstituted oxazoles were established whereby the substitution pattern was established by the structure of the starting nonsymmetrical acyloins. 2-Chloromethyl-4, 5-disubstituted oxazoles were prepared by refinements of an earlier described process whereby chloroacetyl esters of symmetrical and non-symmetrical acyloins were cyclized using an ammonium acetate/acetic acid protocol
建立了形成2、4、5-三取代的恶唑的新途径,从而通过起始的不对称酰基胞苷的结构建立了取代模式。通过改进先前描述的方法制备2-氯甲基-4,5-二取代的恶唑,其中使用乙酸铵/乙酸方案将对称和不对称酰基的氯乙酰基酯环化。进行取代后,然后在温和条件下通过取代安装叠氮化物部分。尽管需要二溴化和碘化的苯基恶唑进行进一步的合成修饰,但发现环化反应对原料中卤素的相对位置非常敏感。