The use of mono-substituted malonic acid half oxyesters (SMAHOs) has been hampered by the sporadic references describing their preparation. An evaluation of different approaches has been achieved, allowing to define the best strategies to introduce diversity on both the malonic position and the ester function. A classical alkylation step of a malonate by an alkyl halide followed by a monosaponification gave access to reagents bearing different substituents at the malonic position, including functionalized derivatives. On the other hand, the development of a monoesterification step of a substituted malonic acid derivative proved to be the best entry for diversity at the ester function, rather than the use of an intermediate Meldrum acid. Both these transformations are characterized by their simplicity and efficiency, allowing a straightforward access to SMAHOs from cheap starting materials.

中文翻译：

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单取代丙二酸半氧酯 (SMAHO) 的制备

描述其制备的零星参考文献阻碍了单取代丙二酸半氧化酯 (SMAHO) 的使用。已经实现了对不同方法的评估，允许定义在丙二酸位置和酯功能上引入多样性的最佳策略。用烷基卤化物对丙二酸酯进行经典的烷基化步骤，然后进行单皂化，可以得到在丙二酸位置带有不同取代基的试剂，包括功能化衍生物。另一方面，取代丙二酸衍生物的单酯化步骤的开发被证明是酯功能多样性的最佳入口，而不是使用中间体 Meldrum 酸。这两种转换的特点是简单高效，