ammonium hydroxide; nitric acid; sodium nitrite in water

1: 2-[(3R,4S)-4-ethyl-5-oxo-tetrahydro-3-furanyl]acetaldehyde; methylamine With potassium carbonate in dichloromethane; benzene 3 h; 2: 4-toluene-sulfonylmethyl isocyanide With triethylamine T=25°C; 168 h; Further stages.;

1: 1) NaH / 1) THF, 0 deg C, 30 min, 2) THF, 0 deg C, 5 min 2: 24 percent / 30percent H2O2 / CH2Cl2 / 1) 0 deg C, 1 h, 2) 25 deg C, 4 h 3: 95 percent / 425 °C / 0.01 Torr 4: 1) (+)-β-chlorodiisopinocamphenylborane, 2) diethanolamine / 1) THF, -30 deg C, 5 days, 2) Et2O, 2 h 5: 48 percent / mercury(II) acetate / 24 h / 135 - 140 °C 6: H2 / 10percent Pd/C / ethanol / 760 Torr 7: 1) K2CO3, 2) triethylamine / 1) benzene, CH2Cl2, 25 deg C, 2 h, 2) CH2Cl2, 7 days View Scheme

1: 24 percent / 30percent H2O2 / CH2Cl2 / 1) 0 deg C, 1 h, 2) 25 deg C, 4 h 2: 95 percent / 425 °C / 0.01 Torr 3: 1) (+)-β-chlorodiisopinocamphenylborane, 2) diethanolamine / 1) THF, -30 deg C, 5 days, 2) Et2O, 2 h 4: 48 percent / mercury(II) acetate / 24 h / 135 - 140 °C 5: H2 / 10percent Pd/C / ethanol / 760 Torr 6: 1) K2CO3, 2) triethylamine / 1) benzene, CH2Cl2, 25 deg C, 2 h, 2) CH2Cl2, 7 days View Scheme

1: 1.) potassium bis(trimethylsilyl)amide / 1.) THF, toluene, -74 deg C, 45 min, 2a.) -74 deg C, 10 min, 2b.) -74 deg C to RT 3: NaNO2, KBr, 2.5 N aq. HBr / 2 h / -9 - -7 °C 4: 82 percent / H2SO4 / 2-methyl-propan-2-ol; dioxane / 18 h 5: 1.) Zn(Ag), Cu(I)Br, Et2AlCl / 1.) THF, hexane, 1 h, 2.) THF, RT, 1.5 h 6: 96 percent / CH2Cl2 / 18 h / Ambient temperature 7: oxalyl chloride, DMF / CH2Cl2 / 1.) 0 deg C, 10 min, 2.) RT, 4 h 8: NaBH4 / dimethylformamide 9: ammonium formate / Pd/C (10percent) / methanol / 1.) RT, 10 min, 2.) 60-70 deg C, 21 h 10: 2 N aq. HCl / methanol View Scheme

2: NaNO2, KBr, 2.5 N aq. HBr / 2 h / -9 - -7 °C 3: 82 percent / H2SO4 / 2-methyl-propan-2-ol; dioxane / 18 h 4: 1.) Zn(Ag), Cu(I)Br, Et2AlCl / 1.) THF, hexane, 1 h, 2.) THF, RT, 1.5 h 5: 96 percent / CH2Cl2 / 18 h / Ambient temperature 6: oxalyl chloride, DMF / CH2Cl2 / 1.) 0 deg C, 10 min, 2.) RT, 4 h 7: NaBH4 / dimethylformamide 8: ammonium formate / Pd/C (10percent) / methanol / 1.) RT, 10 min, 2.) 60-70 deg C, 21 h 9: 2 N aq. HCl / methanol View Scheme

1: 82 percent / H2SO4 / 2-methyl-propan-2-ol; dioxane / 18 h 2: 1.) Zn(Ag), Cu(I)Br, Et2AlCl / 1.) THF, hexane, 1 h, 2.) THF, RT, 1.5 h 3: 96 percent / CH2Cl2 / 18 h / Ambient temperature 4: oxalyl chloride, DMF / CH2Cl2 / 1.) 0 deg C, 10 min, 2.) RT, 4 h 5: NaBH4 / dimethylformamide 6: ammonium formate / Pd/C (10percent) / methanol / 1.) RT, 10 min, 2.) 60-70 deg C, 21 h 7: 2 N aq. HCl / methanol View Scheme

1: 1.) Zn(Ag), Cu(I)Br, Et2AlCl / 1.) THF, hexane, 1 h, 2.) THF, RT, 1.5 h 2: 96 percent / CH2Cl2 / 18 h / Ambient temperature 3: oxalyl chloride, DMF / CH2Cl2 / 1.) 0 deg C, 10 min, 2.) RT, 4 h 4: NaBH4 / dimethylformamide 5: ammonium formate / Pd/C (10percent) / methanol / 1.) RT, 10 min, 2.) 60-70 deg C, 21 h 6: 2 N aq. HCl / methanol View Scheme

1: NaBH4 / dimethylformamide 2: ammonium formate / Pd/C (10percent) / methanol / 1.) RT, 10 min, 2.) 60-70 deg C, 21 h 3: 2 N aq. HCl / methanol View Scheme

1: 1) (+)-β-chlorodiisopinocamphenylborane, 2) diethanolamine / 1) THF, -30 deg C, 5 days, 2) Et2O, 2 h 2: 48 percent / mercury(II) acetate / 24 h / 135 - 140 °C 3: H2 / 10percent Pd/C / ethanol / 760 Torr 4: 1) K2CO3, 2) triethylamine / 1) benzene, CH2Cl2, 25 deg C, 2 h, 2) CH2Cl2, 7 days View Scheme