Reaction Steps
Allyltributyltin (4.35 mL, 14.1 mmol) and Pd(PPh3)4 (0.72 g, 0.64 mmol) were added to a N2-purged, stirred solution of iodide 133 (5.88 g, 12.9 mmol) in DME (80 mL) at 20° C. and the reaction mixture was stirred at reflux temperature under N2 for 8 h. The reaction mixture was cooled and partitioned between EtOAc and brine. The organic layer was separated, dried, and the solvent evaporated. The residue was purified by chromatography, eluting with a gradient (0-5%) of EtOAc/pet. ether, to give alkene 137 (4.75 g, 99%) as a yellow solid: mp (EtOAc/pet. ether) 49-52° C.; 1H NMR δ 8.23 (s, 1H, H-9), 7.74 (s, 1H, H-5), 6.17-6.24 (m, 1H, CH), 5.20-5.34 (m, 2H, CH2), 3.75-3.80 (m, 2H, CH2), 3.59-3.67 (m, 2H, CH2O), 3.13-3.25 (m, 2H, CH2), 2.92-3.04 (m, 2H, CH2), 2.72-2.84 (m, 1H, H-7), 0.87 [s, 9H, SiC(CH3)3], 0.04 [s, 6H, Si(CH3)2]; 13C NMR δ 164.1, 154.1, 148.3, 147.6, 133.0, 132.4, 123.0, 118.2, 114.5, 65.4, 42.0, 41.7, 35.8, 35.5, 25.8 (3), 18.3, −5.41 (2); HRMS (FAB+) calcd for C20H30N3O2Si (MH+) m/z 372.2107, found 372.2110. Anal. calcd for C20H29N3O2Si.¼H2O: C, 63.9; H, 7.9; N, 11.2. Found: C, 63.9; H, 7.7; N, 10.8%.
