hydrogenchloride T=20°C; 16 h;

hydrogenchloride cooling;

toluene-4-sulfonic acid; triethylamine 1.) 70 deg C, 60 min, 2.) CHCl3, RT; Yield given. Multistep reaction. Yields of byproduct given;

di(n-butyl)tin oxide 1.) benzene, reflux, overnight, 2.) 0 deg C; Yield given. Multistep reaction;

di(n-butyl)tin oxide 1.) benzene, reflux, overnight, 2.) 0 deg C; Yield given. Multistep reaction. Yields of byproduct given;

1: 65 percent / pyridine / -35 - 20 °C 2: 93 percent / imidazole, DMAP / dimethylformamide / 1 h 3: 76 percent / Et3N, H2 / Pd/C / ethyl acetate / 24 h / 50 °C / 760 Torr 4: 79 percent / DBU / CH2Cl2 / 3 h / Ambient temperature 5: 1.) BF3*OEt2, 4A MS, 2.) 2,6-lutidine / 1.) CH2Cl2, -60 deg C, 30 min, 2.) CH2Cl2, -20 deg C, 1 h 6: 50 percent / H2, Et3N / Pd/C / ethyl acetate; ethanol / 72 h / 50 °C / 38000 Torr 7: 65 percent / DBU / CH2Cl2 / 6 h / Ambient temperature 8: 69 percent / 4A MS, TMSOTf / CH2Cl2 / 0.33 h / -20 °C 9: 79 percent / Pd(MeCN)2Cl2 / acetone; H2O / Ambient temperature View Scheme

1: toluene / 2 h / Heating 2: Et3N / 1 h / 25 °C 3: NaOMe / methanol / 1 h / 25 °C View Scheme