反应详情

To a mixture of (S)-methyl 2-(tert-butoxycarbonyl)-3-(2-nitrophenylsulfonamido)-propanoate iii (150 mg, 0.37 mmol) in 3 mL of DMF was added potassium carbonate (102 mg, 0.74 mmoL). This mixture was stirred at rt for 20 min followed by the addition of 5-bromo-1-pentene (65 μL, 0.55 mmoL). The reaction mixture was stirred at rt for 2 days. It was then filtered, concentrated and purified by silica gel chromatography (eluting with 25% ethyl acetate in hexane) to give 75 mg (43%) of (S)-methyl 2-(tert-butoxycarbonyl)-3-(2-nitro-N-(pent-4-enyl)phenylsulfonamido)propanoate iv as a yellow solid. 1H NMR (CD3OD, 300 MHz) δ 1.42 (s, 9H), 1.54–1.64 (m, 2H), 1.97 (q, J=7.20 Hz, 2H), 3.37 (m, 2H), 3.57–3.80 (m, 2H), 3.72 (s, 3H), 4.42 (dd, J=8.60, 5.31 Hz, 1H), 4.91–5.01 (m, 2H), 5.69–5.79 (m, 1H), 7.75–7.85 (m, 3H), 8.04 (m, 1H). LC-MS (Method D, retention time: 2.68 min), MS m/z 372 (M++1-Boc).

1. stirringThe reaction mixture was stirred at rt for 2 days
2. filtrationIt was then filtered
3. concentrationconcentrated
4. custompurified by silica gel chromatography (eluting with 25% ethyl acetate in hexane)