Reaction Steps
To a solution of Ph3P═CH2Br (1.43 g, 4 mmol) in THF was added n-BuLi (2M in heptanes, 1.95 mL) at 0° C. under N2. The mixture was stirred for 0.5 h before compound 8 (906 mg, 2 mmol) in THF (20 mL) was added dropwise. The mixture was then stirred for 2 h (monitored by TLC). Sat. NH4Cl was added to quench the reaction and THF was removed by evaporation. The residue was dissolved in CH2Cl2 (50 mL), washed with sat. NaHCO3 and brine, and dried over MgSO4. Column chromatography eluting with EtOAc/Hexane gave 9 (684 mg, 76%) as a light yellow foam: mp 177-179° C.; [α]23D=118.2 (c 0.56, CHCl3); 1H NMR (300 MHz, CDCl3): δ 7.92 (s, 1H), 7.91 (d, J=2.4 Hz, 1H), 7.85 (d, J=9.0 Hz, 1H), 7.31 (s, 1H), 7.23 (dd, J=9.0 Hz, J=2.7 Hz, 1H), 5.86-5.75 (m, 1H), 5.29 (m, 1H), 5.26 (d, J=16.8 Hz, 1H), 5.16-5.04 (m, 2H), 4.59 (d, J=17.4 Hz, 1H), 4.11 (s, 3H), 4.06 (s, 3H), 4.01 (s, 3H), 3.36 (dd, J=16.2 Hz, J=6.0 Hz, 1H), 3.29 (t, J=16.5 Hz, 1H), 1.55 (s, 9H); 13C NMR (75 MHz, CDCl3): δ 157.9, 155.3, 149.8, 148.8, 136.5, 130.4, 126.8, 124.4, 124.2, 123.9, 123.6, 123.1, 116.6, 115.2, 105.1, 104.3, 104.1, 80.3, 77.4, 56.3, 56.1, 55.7, 41.1, 29.8, 28.7 (3×C); ESI-HRMS ([M+Na]+) calcd for C27H31NO5Na 472.2100. found 472.2103.
