کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1197689 | 964659 | 2008 | 5 صفحه PDF | دانلود رایگان |
The influence of boric acid or phenylboronic acid on thermal conversion of levoglucosan in acidic sulfolane was studied. Although levoglucosan was converted to levoglucosenone, furfural and 5-hydroxymethyl furfural (total yield: ∼40 mol%) at 200 °C in sulfolane containing 0.1 wt% H2SO4, addition of boric acid enormously lowered the yields of these, and instead caused the formation of a stable complex in more than 70 mol% yield. Thus, boric acid substantially suppressed the acid-catalyzed dehydration and formation of furfurals from levoglucosan through complex formation. From the 1H NMR spectrum, the chemical structure of this complex was confirmed as α-d-glucofuranose cyclic 1,2:3,5-bisborate, which was readily hydrolyzed quantitatively to glucose by the addition of water. Phenylboronic acid also exhibited similar influences.
Journal: Journal of Analytical and Applied Pyrolysis - Volume 82, Issue 1, May 2008, Pages 78–82