1: 90 percent / MS 4A; N-iodosuccinimide; trimethylsilyl trifluoromethanesulfonate / 1,2-dichloro-ethane; tetrahydrofuran / 6 h / 20 °C 2: H2NNH2*H2O / ethanol / 18 h / Heating 3: pyridine / 21 h / 20 °C 4: 72 percent / potassium tert-butanolate / methanol; tetrahydrofuran / 4 h View Scheme

1: 92 percent / MS 4A, MeOTf / CH2Cl2 / 18 h / Ambient temperature 2: 1.) H2NNH2*H2O; 2.) DMAP / 1.) EtOH, 90 deg C, 24 h; 2.) pyridine, 12 h 3: 90 percent / NaOMe / methanol / 20 h / Ambient temperature View Scheme

1: 90 percent / MeONa / methanol / 0.33 h / 20 °C 2: 87 percent / p-TsOH / acetonitrile / 20 °C View Scheme

sodium methylate; toluene-4-sulfonic acid; acetic acid 1.) methanol, dichloromethane, room temp., 2 h; 3.) N,N-dimethylformamide, 50 deg C, 1 h; Yield given. Multistep reaction;

1: 92 percent / MS 4A, MeOTf / CH2Cl2 / 18 h / Ambient temperature 2: 1.) H2NNH2*H2O; 2.) DMAP / 1.) EtOH, 90 deg C, 24 h; 2.) pyridine, 12 h 3: 90 percent / NaOMe / methanol / 20 h / Ambient temperature View Scheme

1: 90 percent / MS 4A; N-iodosuccinimide; trimethylsilyl trifluoromethanesulfonate / 1,2-dichloro-ethane; tetrahydrofuran / 6 h / 20 °C 2: H2NNH2*H2O / ethanol / 18 h / Heating 3: pyridine / 21 h / 20 °C View Scheme

1: 90 percent / MS 4A; N-iodosuccinimide; trimethylsilyl trifluoromethanesulfonate / 1,2-dichloro-ethane; tetrahydrofuran / 6 h / 20 °C 2: H2NNH2*H2O / ethanol / 18 h / Heating 3: pyridine / 21 h / 20 °C 4: 72 percent / potassium tert-butanolate / methanol; tetrahydrofuran / 4 h View Scheme

1.1: methanol; sodium methylate / 1.5 h / 20 °C / pH 9 2.1: toluene-4-sulfonic acid / N,N-dimethyl-formamide / 20 - 50 °C 3.1: sodium hydride / N,N-dimethyl-formamide; mineral oil / 0.5 h / Inert atmosphere 3.2: 20 °C / Inert atmosphere 4.1: hydrogenchloride; sodium cyanoborohydride / tetrahydrofuran; diethyl ether / 5 h / 0 - 20 °C / Molecular sieve 5.1: N-iodo-succinimide; silver trifluoromethanesulfonate / dichloromethane / 0.17 h / 20 °C / Inert atmosphere View Scheme

Multi-step reaction with 3 steps 1: aq. NaHCO3 / acetone / 3 h / 50 °C2: 1.72 g / pyridine / 16 h / 50 °C3: 67 percent / TMSOTf / CH2Cl2 / 1 h / 20 °C  

Multi-step reaction with 4 steps 1: 90 percent / MeONa / methanol / 0.33 h / 20 °C2: 87 percent / p-TsOH / acetonitrile / 20 °C3: 74 percent / NaH / dimethylformamide / 2 h / 0 °C4: 76 percent / NaBH3CN; HCl; MS-3 A / diethyl ether / 1 h / 0 - 5 °C