Reaction Steps
A 10-mL round bottom flask under nitrogen atmosphere was charged with cis-2-(3,4-dimethoxyphenethoxy)cyclohexan-1-ol (13) (80 mg, 0.28 mmol), anhydrous dichloromethane (3 mL), and anhydrous pyridine (70 μL, 0.86 mmol). After the reaction mixture was cooled to 0° C., a solution of 4-nitro-benzenesulfonyl chloride (95 mg, 0.43 mmol) in anhydrous dichloromethane (1.5 mL) was added dropwise. The reaction was stirred at 0° C. for 30 minutes, and then at room temperature until total consumption of all starting material 13 (20 h), as revealed by TLC (1:1, v/v EtOAc:hexane). The reaction mixture was diluted with dichloromethane (10 mL) and aqueous H2SO4 (5%, 10 mL). After the aqueous layer was extracted with CH2Cl2 (2×10 mL), the organic layers were combined, washed successively with diluted aqueous H2SO4 (5%, 10 mL) and brine (10 mL), dried (anhydrous MgSO4), and concentrated in vacuo to give a yellow oil. Purification of this crude material by elution through a silica gel plug using a mixture of ethyl acetate-hexanes (1:2, v/v) afforded 14 (95 mg, 72%). Rf 0.71 (EtOAc-hexanes, 1:1, v/v); 1H-NMR (400 MHz, CDCl3) δ 1.21-1.69 (m, 8H), 2.01-2.11 (m, 1H), 2.63 (t, 2H, J 6.9 Hz), 3.36-3.38 (m, 1H), 3.43-3.57 (m, 2H), 3.83 (s, 6H, OCH3), 4.84-4.86 (m, 1H), 6.63-6.69 (m, 2H), 6.75 (d, 1H, J 8.1 Hz), 8.01-8.05 (m, 2H), 8.24-8.28 (m, 2H); 13C-NMR (100 MHz, CDCl3) δ 21.19, 21.57, 27.20, 29.00, 35.90, 55.76, 55.87, 69.93, 82.65, 111.07, 112.19, 120.63, 124.06, 128.92, 131.39, 143.45, 147.45, 148.68, 150.33.
