acetic acid; zinc in diethyl ether T=20°C; 1 h;

bis(tricyclohexylphosphine)benzylidene ruthenium(IV) dichloride in dichloromethane T=20°C; 24 h;

1: 81 percent / K2CO3 / acetone / Heating 2: 71 percent / Na2S2O4; NaOH / dimethylformamide; H2O / 1 h / 130 °C 3: 95 percent / pyridine 4: Grubbs'catalyst / CH2Cl2 / 24 h / 20 °C View Scheme

1: 71 percent / Na2S2O4; NaOH / dimethylformamide; H2O / 1 h / 130 °C 2: 95 percent / pyridine 3: Grubbs'catalyst / CH2Cl2 / 24 h / 20 °C View Scheme

1: 95 percent / pyridine 2: Grubbs'catalyst / CH2Cl2 / 24 h / 20 °C View Scheme

2: (CF3CO)2O View Scheme

trifluoroacetic anhydride

1: 99 percent / trifluoroacetic acid 2: 59 percent / K2CO3 / butan-2-one / 6 h / Heating 3: 1.) borane, 2.) NaOH, 30percent H2O2 / 1.) THF, 20 deg C, 15 min, 2.) 20 deg C, 15 min 4: 1.) AlCl3, 2.) conc. HCl / 1.) nitrobenzene, room temperature, 12 h, 2.) water, 20 deg C, 7 d 5: 66 percent / dicyclohexylcarbodi-imide, dimethyl sulphoxide 6: 1.) ethylmagnesium bromide, 3.) conc. H2SO4, HgO View Scheme

trifluoroacetic acid

1: 99 percent / trifluoroacetic acid 2: 59 percent / K2CO3 / butan-2-one / 6 h / Heating View Scheme