Reaction of 2,2"-dithiodibenzaldehyde 1 with activated alkenes 2a-g in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) affords, in one step, 3-substituted 2H-1-benzopyrans 6a-g in yields of up to 67%.
2,2"-二
硫杂二
苯甲醛1与活化烯烃2a-g在
1,8-二氮杂双环[5.4.0]十一烯(
DBU)存在下反应,能够一步合成3-取代的2H-1-苯并
吡喃6a-g,产率最高可达67%。