Guidelines for O‑Glycoside Formation from First Principles

The complexity and irreproducibility of glycosylation reactions retard progress in the glycosciences. Application of the steady-state hypothesis to transient oxocarbenium ion–counterion pair intermediates reveals the importance of concentration, temperature, and other factors in glycosylation stereoselectivity. Guidelines are then adduced for the practice of O-glycosylation reactions on the basis of which more reproducible, practical protocols can be established.