反应 #454137

反应方程式

L-arabinose

HCl MeOH

→

powder

Methyl β-L-arabinopyranoside

溶剂

MeOH

反应条件

后处理

1. 1
   温度The mixture was refluxed for 2 h
2. 2
   浓缩The solution was concentrated to about 3/4 of its volume
3. 3
   其他to give a suspension
4. 4
   其他The solid precipitated
5. 5
   过滤was filtered
6. 6
   洗涤washed with cold MeOH (20 mL)

实验过程

To a suspension of L-arabinose (100 g, 667 mmol) in anhydrous MeOH (450 mL) was added a HCl /MeOH solution (7.3 g dry HCl in 50 mL MeOH) at room temperature under argon atmosphere. The mixture was refluxed for 2 h and cooled down to room temperature. The solution was concentrated to about 3/4 of its volume to give a suspension. The solid precipitated was filtered and washed with cold MeOH (20 mL) to give the first crop as a crystalline powder (35.23 g). The filtrate was concentrated (35° C.) to 1/4 of its volume. The solid precipitated was filtered, washed and dried as above to give the second crop (9.66 g) as a colorless crystalline powder. The concentration and filtration were repeated to afford additional 28.31 g of the product (total 73.2 g, 67%). 1H NMR (D2O) δ 3.30 (s, OCH3, 3H), 3.56 (dd, 1H, H5), 3.73 (m, 1H, H4), 3.77 (dd, 1H, H5), 3.82 (bs, 1H, H2), 4.73 (m, 1H, H1).

来源