Reaction Steps
A solution of 80 (1.00 g, 2.11 mmol, 1 equiv) in benzene (100 mL) was treated with 50% w/v aqueous NaOH (20 mL). Benzyltributylammonium chloride (1.32 g, 4.22 mmol, 2 equiv) was added followed by 5-[(methanesulfonyl) oxy]-1-pentene (1.73 g, 10.53 mmol, 5 equiv). The resulting biphasic mixture was stirred vigorously at 25° C. for 12 h. The layers were allowed to separate and the aqueous portion was extracted with EtOAc (2×30 mL). The combined organic portions were washed with H2O (2×100 mL) and saturated aqueous NaCl (50 mL). Drying (MgSO4), filtration, and concentration was followed by flash chromatography (SiO2, 3.5×14 cm, 5% EtOAc-hexane) to furnish 81 (0.975 g, 1.15 g theoretical, 85%) as a pale yellow solid: mp 69-71° C.; 1H NMR (500 MHz, CDCl3) major rotamer δ 8.34-8.32 (m, 1H), 8.23-8.21 (m, 1H), 7.62-7.49 (m, 4H), 7.42-733 (m, 3H), 6.70 (s, 1H), 5.81-5.71 (m, 1H), 5.34-5.18 (m, 2H), 5.01-4.93 (m, 2H), 3.84 (ddd, J=17.5, 12.6, 7.6 Hz, 1H), 3.37-3.31 (m, 1H), 2.07-2.02 (m, 2H), 1.74-1.65 (m, 2H), 1.31 (s, 9H); 13C NMR (125 MHz, CDCl3) major rotamer δ 155.1, 154.0, 143.2, 137.9, 136.4, 135.4, 132.8, 128.7 (2C), 128.5, 128.2 (2C), 127.2, 126.2, 122.5, 115.0, 107.8, 95.1, 80.1, 70.3, 49.1, 31.3, 28.6, 28.3 (3C), 27.5; IR (film) νmax 3067, 3036, 2974, 2923, 1697, 1615, 1590 cm−1; FABHRMS (NBA-NaI) m/z 544.1337 (M+Na+, C27H30INO3 requires 544.1349).
