ethyl 4-(3-chlorophenyl)-2-hydroxy-5-oxo-2-(trifluoromethyl)-2,3,4,5,6,7-hexahydrocyclopenta[b]pyran-3-carboxylate 在
对甲苯磺酸 作用下,
以
甲苯 为溶剂,
反应 12.0h,
以71%的产率得到ethyl 4-(3-chlorophenyl)-5-oxo-2-(trifluoromethyl)-4,5,6,7-tetrahydrocyclopenta[b]pyran-3-carboxylate