Steric effects are not the cause of the rate difference in hydrolysis of stereoisomeric glycosides.
[structure: see text] A long-lived and plausible explanation as to why glycosides with axial substituents are more reactive than those with equatorial substituents was given in 1955 by Edward based on sterical hindrance being relieved in the transition state. Using model compounds 5, 6, 8, and 10, we here show conclusively that sterical hindrance is not the controlling factor in glycoside hydrolysis.
Jensen
Henrik Helligsø
HH
Department of Chemistry, University of Aarhus, Langelandsgade 140, DK-8000 Aarhus C, Denmark.
Bols
Mikael
M
D005697:Galactosides / Q000737:chemistry; D005960:Glucosides / Q000737:chemistry; D006027:Glycosides / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007700:Kinetics; D008968:Molecular Conformation; D015394:Molecular Structure; D013237:Stereoisomerism; D013329:Structure-Activity Relationship
D005697:Galactosides; D005960:Glucosides; D006027:Glycosides