Reaction Steps
A solution of (Z)-2-(3-trifluoromethylphenyl)-5-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthalenyl)-2-pentenol 5r (0.99 g, 2.4 mmol) in anhydrous pyridine (25 mL) at room temperature under argon was treated with 4-dimethylaminopyridine (0.01 g) and acetic anhydride (0.32 g, 3.1 mmol). The reaction mixture was stirred for 2 h and then partitioned between diethyl ether (100 mL) and 1N HCl solution (50 mL). The ether layer was washed further with saturated sodium chloride solution, dried over anhydrous magnesium sulfate, filtered, and concentrated to give 1.09 g (100%) of the product as a colorless oil. The acetate was used without purification in the next reaction. 1H NMR (300 MHz, CDCl3) δ7.50 (d, J=8 Hz, 1H, 2-ArH), 7.36-7.41 (m, 2H, 2-ArH), 7.17 (d, J=8 Hz, 1H, 2-ArH), 7.11 (d, J=8 Hz, 1H, 5-ArH), 6.98 (d, J=2 Hz, 1H, 5-ArH), 6.82 (dd, J=2, 8 Hz, 1 Hz, 5-ArH), 5.89 (t, J=7.5 Hz, 1H, C=CH), 4.73 (s, 2H, CH2OAc), 2.61 (t, J=7 Hz, 2H, ArCH2), 2.24 (q, J=7 Hz, 2H, ArCH2CH2), 1.99 (s, 3H, CH3C=O), 1.64 (s, 4H, CH2CH2), 1.24 (s, 6H, 2'CH3), and 1.22 (s, 6H, 2×CH3); 13C NMR (75 MHz, CDCl3) δ170.66 (C=O), 144.70, 142.52, 138.81, 137.91, 134.89, 133.09, 131.95, 128.67, 126.48, 126.45, 125.73, 125.36, 125.31, 124.02, 68.68 (CH2OAc), 35.33, 35.14, 35.09, 34.12, 31.87, 31.81, 30.67, and 20.89; IR (film) 2960, 2925, 2860, 1745 (C=O), 1325, 1225, 1165, and 1130 cm-1 ; MS (DCI) m/e 399 (M+ --OAc).
