Exclusive <i>α</i>-Coupling in the Aldol Reaction of Unsaturated Trimethylsilyl Esters: An Efficient and Practical Direct Synthesis of Unsaturated <i>β</i>-Hydroxy Acids
作者:Moncef Bellassoued、Jérôme Grugier、Nathalie Lensen、Audrey Catheline
DOI:10.1021/jo020128u
日期:2002.8.1
give exclusively the alpha-condensation products in excellent yields. The unsaturated beta-hydroxy acids thus obtained were directly identified, and the usual conversion into their methyl esters with diazomethane was not necessary. Unsaturated ketones underwent Michael reaction through alpha-addition leading to the unsaturated 5-oxo acids.
丁烯酸三甲基甲硅烷基酯和丁烯酸3-甲基丁酯的烯醇锂与醛和饱和或芳香族酮在-70℃下反应,以优异的产率仅得到α缩合产物。由此获得的不饱和β-羟基酸被直接鉴定,并且不需要用重氮甲烷通常转化为它们的甲酯。不饱和酮通过α加成反应发生迈克尔反应,从而导致不饱和5-氧代酸。