Synthesis of 3-Aminotropones fromN-Boc-Protected Furan-2-amine (=tert-Butyl Furan-2-ylcarbamate; Boc=(tert-Butoxy)carbonyl) by Cycloaddition Reactions and Subsequent Rearrangement
作者:Ángel M. Montaña、Juan A. Barcia、Gabriele Kociok-Köhn、Mercè Font-Bardia、Xavier Solans
DOI:10.1002/hlca.200890024
日期:2008.2
The 3-aminotropones (=3-aminocyclohepta-2,4,6-trien-1-ones) 4 were prepared in two steps by i) a [4+3] cycloaddition reaction between a conveniently substituted α,α′-dihalo ketone 1 and a furan-2-amine derivative 2 functionalized at C(2) by a protected amino group (3), and ii) a base-induced molecular rearrangement of the cycloadduct 3via cleavage of the O-bridge. A mechanism for the formation of 3-aminotropones
3-aminotropones(= 3-aminocyclohepta -2,4,6-三烯-1-酮)4,通过两个步骤制备我)一个方便取代之间的[4 + 3]环加成反应α,α '-dihalo酮1和呋喃-2-胺衍生物2在C(2)处通过受保护的氨基(3)官能化,并且ii)通过O桥的裂解碱基诱导的环加合物3分子重排。一种用于3-aminotropones形成机构被提出了[(的初始去质子化的基础上,叔丁氧基)羰基]氨基(BocNH)基团的3,然后进行O桥打开,酸碱平衡,最后消除烷氧基铝酸盐,得到共轭稳定的类肌钙蛋白系统(方案7)。