ethyl 2-(2-ethoxy-2-oxoethyl)-2,2',3',5,5',6,6',7-octahydrospiro[[1,2,4]oxadiazolo[2,3-a]pyridine-8,4'-pyran]-2-carboxylate 以
环己基苯 为溶剂,
反应 15.0h,
以23%的产率得到ethyl 3'-hydroxy-4'-oxo-2,3,4',5,6,6',7',8'-octahydrospiro[pyran-4,9'-pyrido[1,2-a]pyrimidine]-2'-carboxylate