Reaction Steps
5-Bromo-6-methyl-3-(1-t-butyloxycarbonyl-(2S)-azetidinylmethoxy)pyridine (0.95 g, 2.7 mmol, Step 34a above) was treated with vinyl tributyltin (1.62 mL, 5.56 mmol) and tetrakis(triphenylphosphino)palladium(0) (0.29 g, 0.25 mmol) in toluene (30 mL) at 90° C. overnight. The reaction was cooled to ambient temperature and chromatographed on silica gel with 2:1 hexane-EtOAc eluent to provide 6-methyl-5-vinyl-3-(1-t-butyloxycarbonyl-(2S)-azetidinylmethoxy)pyridine (0.49 g, 60%): MS (CI/NH3) m/z: 305 (M+H)+; 1H NMR (300 MHz, CDCl3) δ1.42 (s, 9H), 2.22-2.38 (m, 2H), 2.52 (s, 3H), 3.91 (dt, J=2, 6 Hz, 2H), 4.13 (dd, J=3, 10 Hz, 1H), 4.30-4.36 (m, 1H), 4.49-4.55 (m, 1H), 5.40 (dd, J=1, 11 Hz, 1H), 5.64 (dd, J=1, 17 Hz, 1H), 6.84 (dd, J=11, 17 Hz, 1H), 7.32 (d, J=3 Hz, 1), 8.13 (d, J=3 Hz, 1H). The product from above (0.47 g,1.53 mmol) was treated with 8 mL of 1:1 TFA-methylene chloride at 0° C. for 2 hours. The volatile components were evaporated in vacuo, and the residue was diluted with saturated aqueous sodium bicarbonate and extracted with CH2Cl2. The combined organic layers were washed with water and dried over MgSO4 to provide the product (277 mg, 89% yield). Half of the sample was dissolved in ether and treated with 1 M HCl in ether to provide 85 mg of the title compound as an off-white solid: mp 154-155° C.; [α]D −8.9 (c 0.45, MeOH); 1H NMR (CD3OD) δ2.63-2.77 (m, 2H), 2.74 (s, 3H), 4.08-4.16 (m, 2H), 4.52-4.64 (m, 2H), 4.85-4.95 (m, 1H), 5.80 (d, J=11 Hz, 1H), 6.15 (d, J=17 Hz, 1H), 7.02 (dd, J=11, 17 Hz, 1H), 8.36 (d, J=2 Hz), 1H, 8.48 (d, J=2 Hz, 1H); MS (CI/NH3) m/z; 205 (M+H)+; Anal. Calcd for C12H16N2O.2.1 HCl: C, 51.32; H, 6.50; N, 9.97. Found: C, 51.60; H, 6.21; N, 9.82.
