Medium-sized cyclophanes. Part 57. Synthesis, conformations and stereodynamics of [2.n]metacyclophan-1-enes and their conversion to [2.n]metacyclophan-1-ynes
作者:Takehiko Yamato、Koji Fujita、Takao Abe、Hirohisa Tsuzuki
DOI:10.1039/b010205i
日期:——
anti- and syn-[2.8]Metacyclophan-1-enes 3a, which are both conformationally rigid structures, were prepared in good yields by a McMurry cyclization of 1,8-bis(5-tert-butyl-3-formyl-2-methoxyphenyl)octane 2a. Similarly, McMurry cyclization of 1,10-bis(5-tert-butyl-2-methoxy-3-formylphenyl)decane 2b afforded (E)- and (Z)-[2.10]-metacyclophan-1-enes 3b in good yields. The assignment of the E and Z structures
抗-和顺- [2.8] Metacyclophan -1-烯烃3a中,这两者都是构象刚性结构,是在良好的产率通过一个的McMurry环化来制备1,8-双(5-叔丁基-3-甲酰基-2-甲氧基苯基)辛烷 2a。同样,麦克默里环化 的 1,10-双(5-叔丁基-2-甲氧基-3-甲酰基苯基)癸烷 2b以良好的产率提供了(E)-和(Z)-[2.10]-间环phan-1-烯 3b。E和Z结构的分配通过以下方法确认1 H-NMR 分析和单晶X射线衍射研究。 溴化(E)-和(Z)-3b的苄基三甲基三溴化铵仅提供桥连双键的顺式加合物4b。当用钾叔丁醇在80℃下回流HOBu t 3小时后,溴加成物meso - 4b以93%的收率得到了脱氢溴化产物[2.10] metacyclophan-1-yne 6b,以及1-bromo [2.10] metacyclophan-1-ene 5b。产率7%;与溴加合物的相同反应DL