pyridinium bis(ethoxycarbonyl)methylide 、
2-benzoyl-2-(2,3-diphenyl-2-cyclopropenylidene)acetonitrile 以
苯 为溶剂,
反应 145.0h,
以60%的产率得到rac-diethyl (3a1R,9aR)-3-cyano-2,4,10-triphenyl-3a1,9a-dihydro-7H-3a,4,7-(epimethanetriyl)pyrano[2,3,4-hi]indolizine-5,5(4H)-dicarboxylate