Alkoxycarbonyl-Substituted 3-Trifloxypropene Iminium Salts and Iminium-Substituted Δ<sup>2,3</sup>-Butenolides: Synthesis and Reactivity toward Nucleophiles
作者:Gerhard Maas、Joachim Nikolai
DOI:10.1055/s-2003-42440
日期:——
Triflic anhydride reacts regioselectively with the ethoxycarbonyl-substituted enaminones 6a-h to give the novel 3-trifloxypropene iminium salts 7a-d or iminium-substituted Î2,3-butenolides 8a-d and 9a-d in good yields. Hydride reduction of the iminium salts 7a,b affords new 2-dialkylamino-4-trifloxy-but-3-enoates 13a,b, while mild hydrolysis generates 2-oxo-4-trifloxy-butenoates 14a,b . Butenolides 8b,d, and 9c react with methyl hydrazine to afford 4-dialkylamino-pyridazin-3(2H)-ones 12a-c.
三氟酸酐与乙氧基羰基取代的烯酮 6a-h 发生区域选择性反应,以良好的产率生成新型 3-三羟基丙烯亚胺盐 7a-d 或亚胺取代的 δ2,3-丁烯内酯 8a-d 和 9a-d。亚铵盐 7a,b 的氢化还原生成新的 2-二烷基氨基-4-三羟基丁-3-烯酸盐 13a,b,而温和水解生成 2-氧代-4-三羟基丁烯酸盐 14a,b。丁烯内酯 8b,d 和 9c 与甲基肼反应生成 4-二烷基氨基哒嗪-3(2H)-酮 12a-c。