Synthesis and stereochemistry of some 3-substituted 2-methylbut-2-enoic acid derivatives
作者:R. Brettle、P. C. Hydes、D. Seddon、J. R. Sutton、R. Tooth
DOI:10.1039/p19730000345
日期:——
identical with a product from the oxidation of ethyl α-methylacetoacetate by lead dioxide, has been synthesisedfrom ethyl (E)-3-halogeno-2-methylbut-2-enoates by highly stereo-selective substitution reactions, and further reactions of this type are described. The base-catalysed addition of ethanol to ethyl 2-methylbuta-2,3-dienoate is also highly stereoselective and gives ethyl (E)-3-ethoxy-2-methylbut-2-enoate
紫外线(E)-2,4,5-三甲基-3-氧杂己烷-4-二烯二酸酯的辐射得到(Z)-异构体。讨论了这两个异构体和其他3-取代的2-甲基丁-2-烯酸衍生物的nmr光谱。(E)-2,4,5-trimethyl-3-oxahex-4-enenateate (E)-2,4,5-trimethyl-3-oxahex-4-enenioate由乙基(E)-3-卤代-2合成,与α-甲基乙酰乙酸乙酯被二氧化铅氧化的产物相同。-通过高度立体选择性取代反应的-甲基丁-2-烯酸酯,以及这种类型的进一步反应被描述。碱催化的乙醇向2-甲基丁-2,3-二烯乙基乙酯的加成反应也具有很高的立体选择性,可得到(E)-3-乙氧基-2-甲基丁-2-烯酸酯。