反应 #2171072

反应方程式

carbontetrabromide

triphenylphosphine

9a

15-Hydroxy-4,7,10,13-tetraoxapentadecanoic Acid tert-Butyl Ester

ethanol

→

10a

收率 47.5%

15-Bromo-4,7,10,13-tetraoxapentadecanoic Acid tert-Butyl Ester

收率 47.5%

溶剂

dichloromethane

toluene

反应条件

后处理

1. 1
   干燥dried over anhydrous sodium sulfate and 4A molecular sieves in dichloromethane
2. 2
   过滤The mixture was filtered
3. 3
   浓缩concentrated
4. 4
   过滤the reaction mixture was filtered through a silica gel bed
5. 5
   浓缩concentrated
6. 6
   其他purified by silica gel chromatography

实验过程

Alternatively, 1.61 g (5.03 mmol) of 9a was co-evaporated successively with 100% ethanol and toluene, then dried over anhydrous sodium sulfate and 4A molecular sieves in dichloromethane. The mixture was filtered and concentrated. To the dried compound (1.42 g) in 20 ml of dichloromethane was added 2.48 g of carbontetrabromide (CBr4, 7.47 mmol) and 1.50 g of triphenylphosphine (PPh3, 5.71 mmol). After stirring under an atmosphere of argon overnight, the reaction mixture was filtered through a silica gel bed, then concentrated and purified by silica gel chromatography. (EtOAc/Hexane Gradient starting at a ratio of 1:2 and changing to a ratio of 2:3) to yield 0.92 g of the 10a. (62%). Rf=0.64 (EtOAc); 1H NMR (CDCl3) 3.785 (t, 2H, J=6.3+6.3 Hz), 3.68 (t, 2H, J=6.5+6.5 Hz), 3.650 (m, 8H), 3.615 (m, 4H), 3.462 (t, 2H, J=6.3+6.4 Hz), 2.491 (t, 2H, J=6.5+6.5 Hz), 1.434 (s, 9H); 13C NMR 171.063, 80.656, 71.368, 70.831, 70.764, 70.706, 70.678, 70.545, 67.061, 36.431, 30.474, 28.263; MS m/z 408.74 (M+Na)+, 406.70, 405.70, 404.73.

来源