Bromine → HCID 68541141, compound

Participants

Reaction Conditions

Reaction Steps

To a solution containing 0.54 g (1.12 mmol) of 2 in 5 mL of anhydrous CH2Cl2 at 0° C. under argon was added 0.21 g (0.07 mL, 1.34 mmol) of Br2. The reaction mixture was stirred at 0° C. for 20 min then diluted with 20 mL of CH2Cl2 and washed with 3% aq NaHSO3. The organic layer was separated, dried (MgSO4) and concentrated under diminished pressure. The crude residue was then purified by flash chromatography on a silica gel column (26×4 cm). Elution with 2:1 hexanes-ethyl acetate gave 3 as a colorless oil: yield 0.49 g (96%); silica gel TLC Rf 0.21 (2:1 hexanes-ethyl acetate); 1H NMR (CDCl3) δ 0.94 (q, 6H, J=7.5 Hz), 1.25 (d, 3H, J=6.3 Hz), 1.62 (m, 4H), 2.23 (m, 4H), 4.04 (m, 1H), 4.11 (dd, 1H, J=3.3 and 1.8 Hz), 4.64 (q, 2H, J=12.3 Hz), 5.30 (t, 1H, J=9.9 Hz), 5.57 (dd, 1H, J=10.2 and 3.3 Hz), 6.34 (d, 1H, J=0.6 Hz) and 7.33 (m, 5H); 13C NMR (CDCl3) δ 13.71, 17.11, 18.31, 18.47, 35.99, 36.11, 69.67, 70.27, 71.26, 73.37, 79.20, 86.35, 127.96, 128.18, 128.57, 137.18, 172.31 and 172.68. Note: this compound must be used promptly; product decomposes rather rapidly (1-2 days).

Provenance & Evidence