Reaction Steps
A solution of 4c (190 mg, 0.67 mmol) in anhydrous THF (530 μL) was added dropwise to a solution of nBuLi (2.5 M in hexanes, 410 μL, 1.00 mmol) in anhydrous THF (440 μL) at room temperature. After one hour, the solution was cooled to −78° C. and methyl iodide (170 μL, 2.67 mmol) was added. The resulting solution was warmed to room temperature over 12 hours, and the reaction was quenched by the addition of saturated aqueous NH4Cl. Water (5 mL) was added and the solution was extracted with CH2Cl2 (3×10 mL). Combined organic fractions were dried (Na2SO4), filtered, and concentrated. The residue was purified via column chromatography (SiO2, 6:1 Hexane:EtOAc) to afford 5c as a yellow oil (157 mg, 79%): 1H NMR (CDCl3, 500 MHz) δ 6.70 (d, J=9.0 Hz, 1H), 6.61 (d, J=9.0 Hz, 1H), 5.10 (s, 2H), 5.08 (s, 2H), 4.34 (quintet, J=6.1 Hz, 1H), 3.78 (q, J=7.1 Hz, 2H), 3.67 (q, J=7.1 Hz, 2H), 2.13 (s, 3H), 1.23 (d, J=6.1 Hz, 6H), 1.24-1.15 (m, 6H); 13C NMR (CDCl3, 125 MHz) δ 150.3, 146.6, 145.3, 122.7, 113.7, 110.1, 97.3, 94.0, 71.5, 65.4, 64.2, 29.4, 22.2, 15.2, 15.2, 9.9; IR (film) νmax 2924, 2853, 2359, 2339, 1591, 1483, 1113, 1057, 974 cm−1; HRMS (ESI+) m/z: [M+H]+ calcd for C16H26O5, 299.1858. found, 299.1909.
