تفاعل #75465

معادلة التفاعل

methyl-9-hydroxy-nonanoate

CBr4

PPh3

→

Methyl-9-bromo-nonanoate

المذيبات

CH2Cl2

ظروف التفاعل

المعالجة

1. 1
   غسيلwashed repeatedly with Et2O (8×10 mL washes)
2. 2
   تركيزconcentrated under reduced pressure
3. 3
   أخرىChromatography (SiO2, 5 cm×15 cm, hexanes) afforded the intermediate as a clear, colorless oil (1.02 g, 1.47 g theorectical, 69.5%)

الإجراء التجريبي

A solution of methyl-9-hydroxy-nonanoate (1.1 g, 5.85 mmol, 1.0 equiv) in CH2Cl2 (30 mL, 0.2 M) at 0° C. was treated successively with CBr4 (2.5 g, 7.54 mmol, 1.3 equiv) and PPh3 (2.15 g, 8.19 mmol, 1.4 equiv) and the reaction mixture was stirred at 4° C. for 10 h. The reaction mixture was then concenctrated under reduced pressure and washed repeatedly with Et2O (8×10 mL washes). The Et2O washes were combined and concentrated under reduced pressure. Chromatography (SiO2, 5 cm×15 cm, hexanes) afforded the intermediate as a clear, colorless oil (1.02 g, 1.47 g theorectical, 69.5%): 1H NMR (CDCl3, 250 MHz) d 3.64 (s, 3H, C(O)OCH3), 3.38 (t, 2H, J=6.8 Hz, CH2Br), 2.29 (t, 2H, J=7.4 Hz CH2C(O)OCH3), 1.83 (p, 2H, CH2CH2Br), 1.63 (m, 2H, CH2CH2C(O)OCH3) 1.47-1.28 (m, 8H, alkyl protons).

المصدر