1-Trifluoromethylvinyl vinyl ketones are treated with trimethylsilyl trifluoromethanesulfonate in CH2Cl2-1,1,1,3,3,3-hexafluoro-2-propanol to afford 5-trifluoromethyl-2-cyclopentenones. Both acyclic and cyclic substrates furnish the corresponding cyclized products in good to excellent yields with defined placement of the endocyclic double bond due to the strong electronic effect exerted by the trifluoromethyl group.
1-三
氟甲基
乙烯基乙烯酮在
二氯甲烷-
1,1,1,3,3,3-六氟-2-丙醇中与三甲基
硅基
三氟甲磺酸酯反应,生成5-三
氟甲基-
2-环戊烯酮。无论是开链还是环状底物,都能以良好至优异的产率得到相应的环化产物,环内双键的位置明确,这是由于三
氟甲基的强烈电子效应所致。