Steric acceleration in the acid-catalysed hydrolysis of 1-adamantyl β-D-glucopyranoside. The origin of the high rates of hydrolysis of tertiary glycosides

Abstract

1-Adamantyl β-D-glucopyranoside is hydrolysed by 0·5M-sulphuric acid at 60·0° 49 times faster than the methyl compound, with >95% glucosyl–oxygen fission; steric acceleration is thus considered to be a major driving force for the high rates of hydrolysis of tertiary glycosides, even though alkyl–oxygen fission to planar cations is probably taking place, as shown inter alia by the close similarity of the hydrolysis rates of t-butyl β-D-gluco- and galacto-pyranosides.