This paper describes a synthesis of 3-acyl-2-alkyl-3-ethoxycarbonylpropanoic acids from ethyl 2-oxoalkanoates and 2-bromoalkanoic acids. These acids are cyclised via intramolecular dehydration to give 2,4-dialkyl-3-ethoxycarbonyl-3-buten-4-olides or are condensed with allylzinc reagents to give the 4-alkenyl-2,4-dialkyl-3-ethoxycarbonyl-4-butanolides.
本文描述了从乙基2-氧
羧酸酯和2-
溴烷酸合成3-酰基-2-烷基-3-乙氧基碳酰基
丙酸。这些酸通过分子内脱
水环化,生成2,4-二烷基-3-乙氧基碳酰基-3-
丁烯-4-内酯,或者与烯丙基
锌试剂缩合,生成4-烯基-2,4-二烷基-3-乙氧基碳酰基-4-内酯。