Reaction of the lithio-derivative of methoxyallene with hydrazones. Part 1: Synthesis and transformation of α-allenyl hydrazines
作者:Valérie Breuil-Desvergnes、Jacques Goré
DOI:10.1016/s0040-4020(01)00030-8
日期:2001.3
methoxyallene reacts with aldehyde hydrazones leading to expected α-allenyl hydrazines when ether is the solvent of the reaction. The yields are good as well as the diastereoselectivity observed in the case of SAMP-hydrazones. These hydrazines are cleanly transformed to N-dialkylamino-3-methoxy-3-pyrrolines when they are reacted with n-BuLi in THF. These compounds are sometimes accompanied by the isomeric
当醚是反应的溶剂时,甲氧基烯丙基的硫代衍生物与醛反应,生成预期的α-烯丙基肼。在SAMP-hydr的情况下,收率和非对映选择性都很好。当这些肼与正丁基锂在THF中反应时,它们会干净地转化为N-二烷基氨基-3-甲氧基-3-吡咯啉。这些化合物有时伴随有异构的4-甲基氮杂环丁烷。该ñ-二烷基氨基-3-甲氧基-3-吡咯啉通过氮-氮键的氢解转化为3-甲氧基-3-吡咯啉,通过用过酸处理转化为3-烷氧基-吡咯,并通过酸性迁移转化为3-氨基吡咯二烷基氨基的基团。就SAMP-肼而言,所获得的3-甲氧基-3-吡咯啉具有高对映体纯度。最后,由于乙醛酸甲酯的形成,通过烯丙基部分的臭氧分解制备α-肼基酯(以及随后的α-氨基酯)的尝试失败了。