Reactions of tetrafluoroethene oligomers. Part 9. Some reactions of perfluoro(1-ethyl-1-methylpropyl)(s-butyl)ethanolide (an α-lactone)
Abstract
The ethanolide (1), prepared by hypochlorite-mediated epoxidation of the ketene CF3(C2F5)2 C[C2F5(CF3)CF]CCO (2), decomposed when warmed at 90 °C for 30 min to give the ketone CF3(C2F5)2CCOCF(CF3)C2F5(3). Reaction of compound (1) with either triethylamine or trimethylamine afforded the olefin (E/Z)-CF3(C2F5)2CCHC(CF3)C2F5(4). Treatment of compound (1) with secondary amines R2NH (R = Et, R2[CH2]5) or primary amines RNH2(R = c-C6H11 or But) afforded oxo amides of the type CF3(C2F5)CFCOCONR2(5) and (6) and CF3(C2F5)CFCOCONHR (7) and (8). With ethylamine and isopropylamine the isolated products were the corresponding oxamides and the olefin (4). With sodium methoxide three products were formed, a trace of olefin (4), 2,4-dimethoxyperfluoro-3-methylpent-2-ene (10), and the oxo ester CF3(C2F5)CFCOCO2Me (11). Sodium ethoxide yielded the olefin (4), the oxo ester CF3(C2F5)CFCOCO2Et (12), and the olefin CF3CFC(CF3)CF(CF3)OEt (13). Reaction of compound (1) with methylmagnesium iodide and ethylmagnesium iodide afforded the esters C2F5(CF3)CC(CO2Me)C(Me)(CF3)C2F5(14) and C2F5(CF3)CC(CO2Et)C(Et)(CF3)C2F5(15) respectively. Treatment of compound (1) with methyl-lithium gave a mixture of two products, the esters (14) and C2F5(CF3)(Me)CC(CO2Me)C(Me)CF3(16), by what appears to be an unusual attack on the ring oxygen. Reaction of compound (1) with ethanethiol gave the ester C2F5(CF3)CFCOCOSEt (17) and the olefin C2F5(CF3)CC(CF3)SEt (18). Compound (1) on reaction with ammonia gave oxamide and the unusual cyanodi-imine CF3C(NH)CH(CN)C(NH)CF3(9). Reaction of compound (1) with tributyl- or triphenyl-phosphine gave olefin (4) again by reaction on the ring oxygen.