3-(2′-cyclopentenyl)-4-hydroxy[1]Benzopyran-2-one(2) or its acetate (3) reacts with pyridine hydrotribromide to give the fused furo chromone (4) in 90% yield, which on refluxing in 50% H2SO4 furnishes the fused furo coumarin (5) in 87% yield.
3-(2'-
环戊烯基)-
4-羟基[1]苯并
吡喃-2-酮(2)或它的
乙酸酯(3)与氢三
溴吡啶反应,以90%的收率得到熔融的
呋喃色酮(4),在回流时将其还原在50%H 2 SO 4中的产率为87%,提供了熔融的
呋喃香豆素(5)。