反応 #58014

反応方程式

2,3,4-tri-O-benzyl-L-fucopyranose

2.3.4-Tri-O-benzyl-L-fucopyranose

compound 6

2.3.4-Tri-O-benzyl-L-fucopyranose

p-nitrobenzoyl chloride

4-nitrobenzoyl chloride

compound 7

4-nitrobenzoyl chloride

→

material

収率 80.0%

2,3,4-Tri-O-benzyl-1-O-p-nitrobenzoyl-α-L-fucopyranose

収率 80.0%

溶媒

CH2Cl2

反応条件

後処理

1. 1
   その他the column purification
2. 2
   ろ過simply filtered through a short column of silica gel
3. 3
   その他This removed the color and other polar material
4. 4
   その他This procedure furnished

実験手順

Since both the α and β isomers yielded the same β-bromide (compound 9), it was decided to skip the column purification and instead use the mixture as such. In this case, 2,3,4-tri-O-benzyl-L-fucopyranose (compound 6) (25 g, 55 mmol) was treated with p-nitrobenzoyl chloride (compound 7) as described above and the crude material (33.0 g) was dissolved in CH2Cl2 (100 mL) and simply filtered through a short column of silica gel. This removed the color and other polar material. This procedure furnished the anomeric mixture of esters (compound 8) as a gummy material (25.7 g, yield 80%).

出典