Synthesis of the first [1,3]benzoxazino[3,2-b][1,2]benzoxazine and its tandem retro-Diels-Alder - Diels-Alder rearrangement to a novel [1,3]benzoxazino[2,3-b][1,3]benzoxazine
作者:Zeev Goldschmidt、Shlomo Levinger、Hugo E. Gottlieb
DOI:10.1016/0040-4039(94)85380-0
日期:1994.9
Thermolysis of 3-methyl-4H-1,2-benzoxazine gave the tetracyclic 12a-methyl-7H,12aH,13H-[1,3]benzoxazino[3,2-b][1,2]benzoxazine, which further rearranged to the isomeric 5a-methyl-5aH,11H,13H-[1,3]benzoxazino[2,3-b][1,3]benzoxazine. Thermolysis of the benzoxazinobenzoxazines gave 2-methyl-4H-1,3-benzoxazine, and o-quinone methide which was trapped by ethyl vinyl ether to give 2-ethoxy-dihydrobenzopyran
3-甲基-4 H -1,2-苯并恶嗪的热解得到四环12a-甲基-7 H,12a H,13 H- [1,3]苯并恶嗪[3,2- b ] [1,2]苯并恶嗪,其进一步重排为异构体5a-甲基-5a H,11 H,13 H- [1,3]苯并恶嗪[2,3- b ] [1,3]苯并恶嗪。苯并恶嗪基苯并恶嗪的热解得到2-甲基-4 H -1,3-苯并恶嗪和邻醌甲基化物,其被乙基乙烯基醚捕获,得到2-乙氧基-二氢苯并吡喃。