Fluorine-Directed Nazarov Cyclizations 2: Regioselective Synthesis of 5-Trifluoromethyl-2-cyclopentenones
作者:Junji Ichikawa、Masaki Fujiwara、Tatsuo Okauchi、Toru Minami
DOI:10.1055/s-1998-1817
日期:1998.8
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。