M. Evans, F. W. Parrish, L. Long
Feb 1, 1967
Citations
0
Influential Citations
71
Citations
Quality indicators
Journal
Carbohydrate Research
Abstract
Abstract The dimethyl acetals derived from acetone, pinacolone, acetophenone, and benzophenone undergo acid-catalyzed acetal exchange with methyl α- D -glucopyranoside. The major products are 4,6-acetals of the sugar; the minor products include methyl 2,3:4,6-di- O -isopropylidene-α- D -glucoside (using the acetone acetal), and isomeric methyl 2,3:4,6-di- O -(1- tert -butylethylidene)-α- D -glucosides (using the pinacolone acetal). These compounds are all examples of a five-membered acetal ring fused trans to a pyranoid ring. Treatment of methyl α- D -glucopyranoside with benzophenone dimethyl acetal gives methyl 6- O -(methoxydiphenylmethyl)-α- D -glucopyranoside in addition to the 4,6-acetal. The 4,6-acetals derived from the four ketones exhibit a wide range of sensitivity to hydrolysis by 75% (v/v) acetic acid.