The formation of 1,6-anhydrohexoses and heptoses by the action of hot alkali on phenyl 3-D-glycosides has been recently suggested by Montgomery, Richtmyer, and Hudson (1, 2) as a method of distinguishing the 3-glycosides from their a isomers. The a isomers form anhydrohexoses in only a few cases, and then much more slowly than do the corresponding ß isomers. Alkyl glycosides were shown to be stable under the same conditions. The preparation of 1,6-anhydro sugars by the action of hot alkali on the phenyl 3-D-glycosides bears a striking similarity to their preparation by the action of hot alkali on trimethyl glycosylammonium halides (3). That the two reactions probably proceed by similar mechanisms has been suggested (2).The mechanism of formation of levoglucosan from a trimethylglycosylammonium halide and hot alkali was suggested by Micheel and Micheel (4) as passing through an unstable intermediate before the formation of the stable glucosan. They suggested that from stereochemical consideration the intermediate in question probably possessed a 1,3-anhydro ring.The formation of a 3-1,6-anhydro ring from a phenyl 3-glycoside or a trimethyl-3-glycosylammonium halide must involve either retention of configuration or an even number of "Walden" inversions. In the light of the recent work of Lucas, Winstein, and co-workers, no mechanism is now postulated which gives SUMMARY A double Walden inversion is proposed as the mechanism for the formation of levoglucosan by the action of hot alkali on phenyl ß--glucoside and trimethylß-D-glucosylammonium halides. It is suggested that a 1,2-anhydro (ethylene oxide) ring is formed, as the intermediate which then reacts by inversion with the proximate hydroxyl of carbon atom number six.

No abstract

No abstract

p ‐Phenylazobenzoyl chloride product: p ‐Phenylazobenzoyl chloride (azoyl chloride)

No abstract