Sodium Iodide → (4S)-4-(2-iodoethyl)-2,2-dimethyl-1,3-dioxolane

Participants

Reaction Conditions

Reaction Steps

To a solution of (S)-2-(2,2-dimethyl-1,3-dioxolan-4-yl)ethanol (1.58 mL, 10.0 mmol) in CH2Cl2 (25 mL) was added DMAP (120 mg, 1.0 mmol) and triethylamine (2.08 mL, 15.0 mmol). The reaction mixture was cooled to 0° C. and methanesulfonyl chloride (12.0 mmol, 0.928 mL) was added slowly dropwise under N2 atmosphere. The reaction mixture was stirred for 2 h (monitored by TLC, 1:2 EtOAc—Hexanes). Saturated NH4Cl solution (20 mL) was added and the mixture was extracted with CH2Cl2. The combined organic layers were washed with brine, dried over anhydrous Na2SO4, filtered and concentrated to provide a yellow oil, which was dissolved in dry acetone (25 ml), followed by addition of NaI (7.5 g, 50 mmol). The reaction mixture was refluxed for 2 h (monitored by TLC, 1:4 EtOAc—Hexanes), cooled to room temperature and water (50 mL) was added. Extraction with ethyl acetate, washing of the combined organic layers with brine, drying over anhydrous Na2SO4, filtration and concentration provided a yellow oil, which was purified by flash chromatography (25% EtOAC-Hexane) to afford the title compound, (S)-4-(2-iodoethyl)-2,2-dimethyl-1,3-dioxolane (0.82 g, 32% over two steps) as a clear oil. 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 1.36 (s, 3H), 1.41 (s, 3H), 1.99-1.16 (m, 2H), 3.25 (dd, J=18.19, 8.84 Hz, 2H), 3.58 (t, J=7.20 Hz, 1H), 4.03-4.13 (m, 1H), 4.13-4.24 (m, 1H). MS (ES) [M+H] calculated for C2H14IO2, 257.00; found 257.08.

Provenance & Evidence