4-dibromo-2,2,6,8-tetramethyl-2H-[1]benzopyran with either organolithium reagents or magnesium generates the novel aryne, 3,4-didehydro-2H-[1]benzopyran. Cycloaddition with dienes gives access to the dibenzo[b,d]pyran system.
3,4-二
溴-2,2,6,8-四甲基-2 H- [1]苯并
吡喃与
有机锂试剂或
镁反应生成新的
芳烃3,4-二氢-2 H- [1]苯并
吡喃。带有二烯的环加成反应可以进入二苯并[ b,d ]
吡喃体系。