作者:Daniel Krois、Harald Lehner
DOI:10.1039/p19820002369
日期:——
[4.2]Metacyclophanes may conveniently be prepared via carbene insertion into appropriately protected [2.2]-and/or [3.2]-metacyclophanediones. Thus, starting from [2.2]-metacyclophane-1,10-dione propylene thioacetal (1)[4.2]metacyclophane (6) was obtained (28%, three steps). For the synthesis of [4.3]metacyclophanes, [4.2] metacyclophane-2,12-dione (5) served as a key compound. Regioselective carbene
通过将卡宾插入适当保护的[2.2]-和/或[3.2] -metacyclophanediones中可以方便地制备[4.2 ] metacyclophanes。因此,从[2.2]-甲基环已烷-1,10-二酮丙烯硫缩醛(1)开始获得[4.2]甲基环已烷(6)(28%,三步)。对于[4.3]甲基环已烷的合成,[4.2]甲基环已-2,12-二酮(5)是关键化合物。区域选择性卡宾插入到(5)中产生[4.3]金属环-2,13-二酮(7),其被转化为[4.3]金属环(8)[从(1)开始为7%]。(6)(60千焦摩尔环反转障碍-1,308 K)和(8)(<38千焦摩尔-1,138 K),通过估计1个H NMR光谱。