Dimethyl 2',7'-dibromospiro[cyclopropene-3,9'-fluorene]-1,2-dicarboxylate 、
pyridazine-4-carboxylic acid cholesteryl ester 以
乙醚 为溶剂,
以51%的产率得到dimethyl 7'-cholesterylcarbonyl-1'H-spiro[2,7-dibromofluorene-9,1'-pyrrolo[1,2-b]pyridazine]-2',3'-dicarboxylate