反応 #1857561

反応方程式

tert-butyl ((3S,7S,8R,9S)-8-butyl-7-hydroxy-9-methyl-2-oxooxonan-3-yl)carbamate

isobutyryl chloride

isobutyryl chloride

→

title compound

収率 56.2%

(2S,3S,4S,8S)-8-((tert-butoxycarbonyl)amino)-3-butyl-2-methyl-9-oxooxonan-4-yl isobutyrate

収率 56.2%

溶媒

pyridine

反応条件

後処理

1. 1
   workup.ADDITIONwas added
2. 2
   温度cooled to room temperature
3. 3
   その他quenched with sat. aq. NH4Cl (5 ml)
4. 4
   抽出extracted with EtOAc (3×10 ml)
5. 5
   乾燥The combined organic extracts were dried over MgSO4
6. 6
   ろ過filtered
7. 7
   濃縮concentrated to dryness
8. 8
   その他The crude residue was purified by flash chromatography (SiO2; EtOAc/hexanes)

実験手順

To a solution of tert-butyl ((3S,7S,8R,9S)-8-butyl-7-hydroxy-9-methyl-2-oxooxonan-3-yl)carbamate (0.405 g, 1.179 mmol) in pyridine (3.4 mL) was added DMAP (0.029 g, 0.236 mmol) followed by the slow addition of isobutyryl chloride (0.247 ml, 2.36 mmol) at room temperature. The reaction was warmed to 50° C. and stirred for 3 h, at which point additional isobutyryl chloride (0.247 ml, 2.36 mmol) was added. The reaction was stirred at 50° C. for an additional 14 h, cooled to room temperature, quenched with sat. aq. NH4Cl (5 ml), and extracted with EtOAc (3×10 ml). The combined organic extracts were dried over MgSO4, filtered, and concentrated to dryness. The crude residue was purified by flash chromatography (SiO2; EtOAc/hexanes) to give the title compound (0.274 g, 0.663 mmol, 56%) as a colorless oil: 1H NMR (400 MHz, CDCl3) δ 5.15 (d, J=8.3 Hz, 1H), 4.91-4.84 (m, 1H), 4.79 (dq, J=10.0, 6.3 Hz, 1H), 4.27-4.16 (m, 1H), 2.60-2.44 (m, 1H), 2.23 (dt, J=13.8, 7.1 Hz, 1H), 2.15-1.99 (m, 3H), 1.73 (tdd, J=13.0, 7.3, 2.3 Hz, 1H), 1.57-1.46 (m, 1H), 1.44 (s, 9H), 1.34 (d, J=6.4 Hz, 4H), 1.33-1.19 (m, 5H), 1.18-1.12 (m, 6H), 1.04-0.94 (m, 1H), 0.87 (t, J=7.0 Hz, 3H); 13C NMR (101 MHz, CDCl3) δ 175.41, 172.91, 154.98, 79.76, 74.44, 73.12, 52.42, 45.44, 34.24, 33.73, 33.32, 30.88, 28.29, 27.38, 23.25, 19.19, 19.03, 18.88, 18.79, 18.02, 13.82; ESIMS m/z 436 ([M+Na]+).

出典