2,6-dimethylpyridine in dichloromethane T=-40°C; Inert atmosphere;

1H-imidazole in dichloromethane; N,N-dimethyl-formamide a.) r.t., 24 h, b.) 55 deg C, 30 h;

pyridine T=0 - 20°C; 23 h;

1: DMAP / CH2Cl2 / 0 °C 2: 2,6-lutidine / CH2Cl2 / 0 °C View Scheme

1.1: O3 / CH2Cl2 / -78 °C 1.2: 90 percent / NaBH4 / methanol / 0 °C 2.1: DMAP / CH2Cl2 / 0 °C 3.1: 2,6-lutidine / CH2Cl2 / 0 °C View Scheme

1: 93 percent / imidazole / CH2Cl2; dimethylformamide / 1.) RT, 15 h, 2.) 45 deg C, 20 h, 3.) 80 deg C, 6 h 2: 1.) ozone, 2.) NaBH4 / 1.) MeOH, pyridine, CH2Cl2, -78 deg C, 1 h, 2.) RT, 12 h 3: 95 percent / pyridine / 2 h / 0 °C View Scheme

1: 93 percent / imidazole / CH2Cl2; dimethylformamide / 1.) RT, 15 h, 2.) 45 deg C, 20 h, 3.) 80 deg C, 6 h 2: 1.) ozone, 2.) NaBH4 / 1.) MeOH, pyridine, CH2Cl2, -78 deg C, 1 h, 2.) RT, 12 h 3: 95 percent / pyridine / 2 h / 0 °C View Scheme

1: 83.3 percent / imidazole / dimethylformamide / 10 h / Ambient temperature 2: 1.) Pb(OAc)4, 2.) NaAlH2(OCH2CH2OCH3)2 / 1.) CH2Cl2, -15 deg C, 15 min, 2.) toluene, RT, 2 h 3: 93 percent / imidazole / CH2Cl2; dimethylformamide / 1.) RT, 15 h, 2.) 45 deg C, 20 h, 3.) 80 deg C, 6 h 4: 1.) ozone, 2.) NaBH4 / 1.) MeOH, pyridine, CH2Cl2, -78 deg C, 1 h, 2.) RT, 12 h 5: 95 percent / pyridine / 2 h / 0 °C View Scheme

1: 1.) Pb(OAc)4, 2.) NaAlH2(OCH2CH2OCH3)2 / 1.) CH2Cl2, -15 deg C, 15 min, 2.) toluene, RT, 2 h 2: 93 percent / imidazole / CH2Cl2; dimethylformamide / 1.) RT, 15 h, 2.) 45 deg C, 20 h, 3.) 80 deg C, 6 h 3: 1.) ozone, 2.) NaBH4 / 1.) MeOH, pyridine, CH2Cl2, -78 deg C, 1 h, 2.) RT, 12 h 4: 95 percent / pyridine / 2 h / 0 °C View Scheme

1: 93 percent / pyridine 2: 99 percent / 2,6-lutidine / CH2Cl2 / -10 °C View Scheme