silver trifluoroacetate Wolff rearrangement;

water; silver trifluoroacetate in tetrahydrofuran; triethylamine 3 h; -25 deg C to room t.;

1: t-Boc-L-valine With O-(benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium tetrafluoroborate; N-ethyl-N,N-diisopropylamine in tetrahydrofuran; N,N-dimethyl-formamide 0.166667 h; 2: diazomethane in tetrahydrofuran; N,N-dimethyl-formamide T=0°C; 0.333333 h;

in diethyl ether 3 h; Ambient temperature;

1: NMM / tetrahydrofuran / 1 h / -25 °C 2: diethyl ether / 2 h / Ambient temperature View Scheme

in diethyl ether 2 h; Ambient temperature; Yield given;