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Indian Journal of Chemistry -Section B (IJC-B) >
IJC-B Vol.45B [2006] >
IJC-B Vol.45B(01) [January 2006] >
| Title: | Vitamin B12 and BF3-etherate as catalysts in synthesis of some C4-C12-alkyl  -D-xylopyranosides |
| Authors: | Petrović, Zorica D
Andjelković, Dejan
Spasojević, Aleksandra |
| Keywords: | Xylopyranosides
vitamin B12
glycosylation
cyanocobalamin |
| Issue Date: | Jan-2006 |
| Publisher: | CSIR |
| IPC Code: | Int.Cl.7 C 07 C |
| Abstract: | Two methods are presented for synthesis of some C4-C12-alkyl -D-xylopyranosides. The first method is the vitamin B12-catalyzed reaction of glycosylation of acetobromoxylose with alkanols (ROH) (C4-C12). The reaction is carried out with 2 mol% of vitamin B12, with respect to xylosyl bromide, under argon at room temperature. Under these conditions peracetylated C4-C12-alkyl -D-xylopyranosides are obtained. Following chromatographic purification these products are de-esterified with a mixture of methanol-triethylamine-water (2:1:1) to give corresponding alkyl -D-xylopyranosides in 50-60% yield. In all cases 3,4-di-O-acetyl-D-xylal is obtained, as the product of reductive elimination of peracetylated xylosyl bromide (15-25%). The second method is synthesis of C4-C12-alkyl -D-xylopyranosides performed by glycosylation of corresponding alkanols with tetra-O-acetyl -D-xylopyranose in the presence of BF3-etherate, as a Lewis acid catalyst. This glycosylation proceeds in only moderate yield (45-55%), but simplicity of this method and avoidance of expensive heavy metal catalysts make such procedure attractive. |
| Page(s): | 272-275 |
| ISSN: | 0975-0983(Online); 0376-4699(Print) |
| Source: | IJC-B Vol.45B(01) [January 2006]
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