A SIMPLE AND RAPID METHOD FOR THE PERMETHYLATION OF CARBOHYDRATES

Article abstract of DOI:10.1016/0008-6215(84)85242-8

As a result of a study of the permethylation of sugars in such dipolar aprotic solvents as methyl sulphoxide, the hitherto accepted role of the CH3SOCH2^- anion is questioned.The HO^- and H⁺ ions appear to be the effective basic agents in these methylation reactions.This conclusion suggested a new method for the permethylation of sugars involving methyl iodide, a solid base (NaOH, KOH, or tert-BuOH/NaOH), and methyl sulphoxide.Excellent yields (98 +/- 2 percent) of permethylation products were obtained in a remarkably short (6-7 min) reaction time.The non-sugar peaks that appear in gas chromatograms of the products of Hakomori methylation were absent when the new reagent was used.