silver trifluoroacetate; triethylamine in tetrahydrofuran; water T=-25 - 20°C; Wolff rearrangement; 3 h;

1.1: Et3N; ClCO2Et / tetrahydrofuran / 0.25 h / -15 - 0 °C 1.2: 71 percent / diethyl ether; tetrahydrofuran / 3 h / 0 - 20 °C 2.1: 83 percent / Et3N; CF3CO2Ag / tetrahydrofuran; H2O / 3 h / -25 - 20 °C View Scheme