toluene-4-sulfonic acid; palladium on activated charcoal in methanol; water T=60 - 80°C; 24 h;

cyclohexa-1,4-diene; palladium on activated charcoal in ethanol; N,N-dimethyl-formamide T=40°C; 10 h;

1: 60 percent / BF3*Et2O / CH2Cl2 / 6 h / 20 °C 2: 100 percent / NaOMe; MeOH / 4 h / 20 °C 3: 95 percent / p-TsOH / dimethylformamide / 24 h / 20 °C 4: 90 percent / NaH / dimethylformamide / 20 h / 20 °C 5: 82 percent / aq. HOAc / 1.5 h / 80 °C 6: 39 percent / 4-dimethylaminopyridine; EDCI / CH2Cl2 / 1 h / 20 °C 7: 28 percent / 1,4-cyclohexadiene / Pd/C / ethanol; dimethylformamide / 10 h / 40 °C View Scheme

1: 95 percent / p-TsOH / dimethylformamide / 24 h / 20 °C 2: 90 percent / NaH / dimethylformamide / 20 h / 20 °C 3: 82 percent / aq. HOAc / 1.5 h / 80 °C 4: 39 percent / 4-dimethylaminopyridine; EDCI / CH2Cl2 / 1 h / 20 °C 5: 28 percent / 1,4-cyclohexadiene / Pd/C / ethanol; dimethylformamide / 10 h / 40 °C View Scheme

1: 96 percent / K2CO3 / dimethylformamide / 20 °C 2: 92 percent / LiOH / methanol; tetrahydrofuran; H2O / 40 h / 20 °C 3: 39 percent / 4-dimethylaminopyridine; EDCI / CH2Cl2 / 1 h / 20 °C 4: 28 percent / 1,4-cyclohexadiene / Pd/C / ethanol; dimethylformamide / 10 h / 40 °C View Scheme

1: 76 percent / DBU / CH2Cl2 / 0.5 h / 20 °C 2: 34 percent / TMDSOTf / diethyl ether / 1 h / 20 °C 3: 100 percent / NaOMe; MeOH / 4 h / 20 °C 4: 95 percent / p-TsOH / dimethylformamide / 24 h / 20 °C 5: 90 percent / NaH / dimethylformamide / 20 h / 20 °C 6: 82 percent / aq. HOAc / 1.5 h / 80 °C 7: 39 percent / 4-dimethylaminopyridine; EDCI / CH2Cl2 / 1 h / 20 °C 8: 28 percent / 1,4-cyclohexadiene / Pd/C / ethanol; dimethylformamide / 10 h / 40 °C View Scheme

1: 60 percent / BF3*Et2O / CH2Cl2 / 6 h / 20 °C 2: 100 percent / NaOMe; MeOH / 4 h / 20 °C 3: 95 percent / p-TsOH / dimethylformamide / 24 h / 20 °C 4: 90 percent / NaH / dimethylformamide / 20 h / 20 °C 5: 82 percent / aq. HOAc / 1.5 h / 80 °C 6: 39 percent / 4-dimethylaminopyridine; EDCI / CH2Cl2 / 1 h / 20 °C 7: 28 percent / 1,4-cyclohexadiene / Pd/C / ethanol; dimethylformamide / 10 h / 40 °C View Scheme

1: 39 percent / 4-dimethylaminopyridine; EDCI / CH2Cl2 / 1 h / 20 °C 2: 28 percent / 1,4-cyclohexadiene / Pd/C / ethanol; dimethylformamide / 10 h / 40 °C View Scheme

1: 34 percent / TMDSOTf / diethyl ether / 1 h / 20 °C 2: 100 percent / NaOMe; MeOH / 4 h / 20 °C 3: 95 percent / p-TsOH / dimethylformamide / 24 h / 20 °C 4: 90 percent / NaH / dimethylformamide / 20 h / 20 °C 5: 82 percent / aq. HOAc / 1.5 h / 80 °C 6: 39 percent / 4-dimethylaminopyridine; EDCI / CH2Cl2 / 1 h / 20 °C 7: 28 percent / 1,4-cyclohexadiene / Pd/C / ethanol; dimethylformamide / 10 h / 40 °C View Scheme

1: 92 percent / LiOH / methanol; tetrahydrofuran; H2O / 40 h / 20 °C 2: 39 percent / 4-dimethylaminopyridine; EDCI / CH2Cl2 / 1 h / 20 °C 3: 28 percent / 1,4-cyclohexadiene / Pd/C / ethanol; dimethylformamide / 10 h / 40 °C View Scheme