Reaktion #58014

Reaktionsgleichung

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

Ausbeute 80.0%

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

Ausbeute 80.0%

Lösungsmittel

CH2Cl2

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigethe column purification
2. 2
   Filtrationsimply filtered through a short column of silica gel
3. 3
   SonstigeThis removed the color and other polar material
4. 4
   SonstigeThis procedure furnished

Vorschrift

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%).

Quelle