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Under nitrogen atmosphere and at −78° C., to a solution of 204 (10.5 g, 44.8 mmol) in anhydrous THF (150 mL) was added a solution of LDA (2.0 M, 28 mL, 56 mmol) and the mixture was stirred for 1 h. 1,4-Dibromobutane (25 ml, 37.5 g, 175 mmol) was then added dropwise over 30 min and the solution allowed to warm to room temperature over 5 h. After stirring at room temperature for an additional 16 h, the reaction was hydrolyzed with water (100 mL) and extracted with Et2O (2×100 mL). The combined organic layers were washed with 10% HCl (2×100 mL), saturated aqueous NaHCO3 solution (100 mL) and water (100 mL). After drying with Na2SO4 (5 g), filtration and concentration, the crude product was purified by flash chromatography (silica gel; ethyl acetate/hexanes=5/95) and dried in high vacuo (0.5 mmHg) at 150° C. for 30 min, affording 205f (14.49 g, 88%) as a clear, viscous oil. 1H NMR (CDCl3): δ 7.19 (d, 2H, J=8.0), 7.08 (d, 2H, J=8.0), 4.11 (q, 2H, J=7.0), 3.35 (t, 2H, J=6.8), 2.43 (d, 2H, J=7.3), 2.10-1.92 (m, 1H), 1.92-1.78 (m, 4H), 1.53 (s, 3H), 1.40-1.28 (m, 2H), 1.17 (t, 3H, J=7.0), 0.88 (d, 6H, J=6.8). 13C NMR (CDCl3): δ 176.17, 141.12, 140.04, 129.14, 125.64, 60.77, 49.80, 44.99, 38.52, 33.51, 33.26, 30.22, 23.55, 22.69, 22.50, 14.19. HRMS (LSIMS, nba): Calcd for C19H30O2Br (MH+): 369.1429, found: 369.1445.

1. stirringAfter stirring at room temperature for an additional 16 h
2. extractionextracted with Et2O (2×100 mL)
3. washThe combined organic layers were washed with 10% HCl (2×100 mL), saturated aqueous NaHCO3 solution (100 mL) and water (100 mL)
4. dry with materialAfter drying with Na2SO4 (5 g), filtration and concentration
5. customthe crude product was purified by flash chromatography (silica gel; ethyl acetate/hexanes=5/95)
6. customdried in high vacuo (0.5 mmHg) at 150° C. for 30 min