1: 96 percent / H2 / 10percent Pd/C / methanol; H2O / 16 h / pH <2 2: 81 percent / 0.25 h / 65 °C 3: 1.) N,N-bis(trimethylsilyl)trifluoroacetamide, pyridine, 2.) SnCl4 / 1.) CH3CN, room temperature, overnight, 2.) CH3CN, 1,2-dichloroethane, -45 deg C to -35 deg C, 0.75 h 4: 1.) NaOCH3, 2.) NaBH4 / 1.) CH3OH, 1 h, 2.) H2O, C2H5OH, 25 deg C, 0.5 h View Scheme

hydrogenchloride; iron in ethanol 20 h; Heating;

in hydrogenchloride; ethanol; water

1.1: CDI / tetrahydrofuran / 1 h / Heating 1.2: 68 percent / t-BuOK / 0 - 5 °C 2.1: 95 percent / Fe; HCl / ethanol / 20 h / Heating View Scheme

1.1: NaClO2; NH2SO3H / methanol; H2O / 1.5 h / 20 °C 2.1: CDI / tetrahydrofuran / 1 h / Heating 2.2: 68 percent / t-BuOK / 0 - 5 °C 3.1: 95 percent / Fe; HCl / ethanol / 20 h / Heating View Scheme

1.1: 95 percent / K2CO3 / dimethylformamide / 4 h / 75 °C 2.1: 72 percent / t-BuOK / dimethylformamide; tetrahydrofuran / 0.17 h / -78 °C 3.1: formic acid / 18 h / 115 °C 4.1: NaClO2; NH2SO3H / methanol; H2O / 1.5 h / 20 °C 5.1: CDI / tetrahydrofuran / 1 h / Heating 5.2: 68 percent / t-BuOK / 0 - 5 °C 6.1: 95 percent / Fe; HCl / ethanol / 20 h / Heating View Scheme

1.1: 72 percent / t-BuOK / dimethylformamide; tetrahydrofuran / 0.17 h / -78 °C 2.1: formic acid / 18 h / 115 °C 3.1: NaClO2; NH2SO3H / methanol; H2O / 1.5 h / 20 °C 4.1: CDI / tetrahydrofuran / 1 h / Heating 4.2: 68 percent / t-BuOK / 0 - 5 °C 5.1: 95 percent / Fe; HCl / ethanol / 20 h / Heating View Scheme

1.1: formic acid / 18 h / 115 °C 2.1: NaClO2; NH2SO3H / methanol; H2O / 1.5 h / 20 °C 3.1: CDI / tetrahydrofuran / 1 h / Heating 3.2: 68 percent / t-BuOK / 0 - 5 °C 4.1: 95 percent / Fe; HCl / ethanol / 20 h / Heating View Scheme