The influence of boric acid on the acetylation of aldoses: ‘one-pot’ syntheses of penta-O-acetyl-β-D-glucofuranose and its crystalline propanoyl analogue
作者:Richard H. Furneaux、Phillip M. Rendle、Ian M. Sims
DOI:10.1039/b002841j
日期:——
When glucose and boric acid are heated in acetic acid a soluble compound forms from which, with acetic anhydride and catalytic amounts of sulfuric acid, a mixture consisting of >90% of the glucofuranose per-acetates (αâ¶Î² ratio 1â¶1.8) is obtained in high yield. In the absence of the sulfuric acid partial acetylation takes place and penta-O-acetyl-β-D-glucofuranose (αâ¶Î² ratio 1â¶52) is obtainable in good yield by removal of boric acid and completion of the esterification by addition of acetic anhydride and pyridine. A new, crystalline glucofuranose, penta-O-propanoyl-β-D-glucofuranose, is obtained in 58% yield in a âone-potâ procedure using boric acid.
The effects of boric acid on the acid-catalysed acetylation of other aldo-hexoses and -pentoses suggest that the synthesis of furanosyl per-esters could be successful with xylose and idose as well as with glucose.
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FromD-Glucose to Biologically PotentL-Hexose Derivatives: Synthesis of ?-L-Iduronidase Fluorogenic Detector and the Disaccharide Moieties of Bleomycin A2 and Heparan Sulfate
A novel and convenient route for the synthesis of biologically potent and rare L-hexose derivatives from D-glucose is described. Conversion of diacetone-alpha-D-glucose (14) into 1,2:3,5-di-O-isopropylidene-beta-L-idofuranose (19) was efficiently carried out in two steps. Orthogonal isopropylidene rearrangement of compound 19 led to 1,2:5,6-di-O-isopropylidene-beta-L-idofuranose (27), which underwent
Efficient Synthesis of 1,2,3,4,6-Penta-<i>O</i>-acetyl-<scp>L</scp>-idopyranose
作者:Shang-Cheng Hung、Chien-Sheng Chen
DOI:10.1002/jccs.200000173
日期:2000.12
An efficientsynthesis of 1,2,3,4,6-penta-O-acetyl-L-idopyranose 2 from 3,5-O-benzylidene-1,2-O-isopropylidene-α-D-glucofuranose in five steps in 45% overall yield via hydroboration of enol ether, hydrolysis of L-idofuranosyl sugar and acetolysis of 1,6-anhydro-β-L-idopyranose as key steps is described here.