作者:Alexander Bayer、Martin E. Maier
DOI:10.1016/j.tet.2004.05.082
日期:2004.7
A range of double unsaturated amides (15, 19, and 21), obtained by cross-coupling reactions was reacted with aldehydes to hemiaminals. Heating the hemiaminals in the presence of Ac2O and pyridine affected clean conversion to the corresponding enamides, such as 42, 45, and 47. Alternatively, N,S-acetals were prepared which were oxidized to the sulfones. Treatment with base also gave the enamides, favoring
双不饱和酰胺(的范围15,19,和21),通过交叉偶联反应得到的与醛hemiaminals反应。在AC的存在下加热hemiaminals 2 O和吡啶影响完全转化为相应的烯酰胺,如42,45,和47。或者,制备N,S-缩醛,将其氧化为砜。用碱处理也得到了酰胺,有利于顺式异构体。但是,这种方法不太通用。这些方法的应用导致了天然产物Lansiumamide-A(30 _ cis),Lansiumamide-I(31)和lansiumamide-B(32)。