1H-imidazole in N,N-dimethyl-formamide 24 h; Ambient temperature;

1: 99 percent / methanol / Heating 2: 98 percent / imidazole / dimethylformamide / 24 h / Ambient temperature View Scheme

1-chloroethyl chlorocarbonate in methanol T=20°C; 3.5 h;

1: 1) lithium diisopropylamide / 1) THF, -78 deg C, 1 h, 2) -50 deg C 2: DIBAL / tetrahydrofuran; toluene / 2 h / -78 °C 3: 1) Zn-powder, 2) trimethylsilyl chloride / 1) THF, r.t., 15 min, 2) r.t., 45 min 4: 1) Me3OBF4, 2) aq.Na2CO3 / 1) CH2Cl2, r.t., 2 h, 2) 6 h 6: 88.5 percent / p-toluenesulfonic acid / CH2Cl2 / Ambient temperature 7: tetrabutylammonium fluoride / tetrahydrofuran / 1 h / Ambient temperature 8: 94 percent / pyridine / CHCl3 / a) 0 deg C, 6 h, b) r.t., overnight 9: 1) CuCN / 1) ether, -78 to -40 deg C, 2) ether, -78 to -20 deg C, then 2 h 10: 64 percent / MeI, CaCO3 / acetonitrile; H2O / 24 h / 35 °C 11: 88 percent / p-toluenesulfonic acid / ethanol / 2 h / 55 °C View Scheme

1: 1) lithium diisopropylamide / 1) THF, -78 deg C, 1 h, 2) -50 deg C 2: DIBAL / tetrahydrofuran; toluene / 2 h / -78 °C 3: 1) Zn-powder, 2) trimethylsilyl chloride / 1) THF, r.t., 15 min, 2) r.t., 45 min 4: 1) Me3OBF4, 2) aq.Na2CO3 / 1) CH2Cl2, r.t., 2 h, 2) 6 h 6: 88.5 percent / p-toluenesulfonic acid / CH2Cl2 / Ambient temperature 7: tetrabutylammonium fluoride / tetrahydrofuran / 1 h / Ambient temperature 8: 94 percent / pyridine / CHCl3 / a) 0 deg C, 6 h, b) r.t., overnight 9: 1) CuCN / 1) ether, -78 to -40 deg C, 2) ether, -78 to -20 deg C, then 2 h 10: 58 percent / MeI, CaCO3 / acetonitrile; H2O / 24 h / 35 °C 11: 90 percent / p-toluenesulfonic acid / ethanol / 2 h / 55 °C View Scheme

1: 1) lithium diisopropylamide / 1) THF, -78 deg C, 1 h, 2) -50 deg C 2: DIBAL / tetrahydrofuran; toluene / 2 h / -78 °C 3: 1) Zn-powder, 2) trimethylsilyl chloride / 1) THF, r.t., 15 min, 2) r.t., 45 min 4: 1) Me3OBF4, 2) aq.Na2CO3 / 1) CH2Cl2, r.t., 2 h, 2) 6 h 6: 88.5 percent / p-toluenesulfonic acid / CH2Cl2 / Ambient temperature 7: tetrabutylammonium fluoride / tetrahydrofuran / 1 h / Ambient temperature 8: 94 percent / pyridine / CHCl3 / a) 0 deg C, 6 h, b) r.t., overnight 9: 76 percent / LiAlH4 / diethyl ether / 48 h / Heating 10: MeI, CaCO3 / acetonitrile; H2O / 24 h / 35 °C 11: p-toluenesulfonic acid / ethanol / 2 h / 55 °C View Scheme