5-[(E)-2-dibenzofuran-4-ylethenyl]-2-methoxy-3,3-dimethyl-1-oxido-2,4-dihydropyrrol-1-ium 、
丁炔二酸二甲酯 以
甲苯 为溶剂,
以85%的产率得到(3aRS,6RS,E)-dimethyl 3a-[2-(dibenzofuran-4-yl)ethenyl]-6-methoxy-5,5-dimethyl-3a,4,5,6-tetrahydropyrrolo[1,2-b]isoxazole-2,3-dicarboxylate