The hetero Diels-Alder approach to carbohydrate-containing molecular scaffolding

The hetero Diels-Alder reactions between α,α’-dioxothiones, α-imino-α’-oxothiones or orthothioquinones and glycals represent an effective way to prepare α- or β-, O- or N-glycosides with impressive chemo-, regio- and diastereoselectivity. The glycoderivatives so obtained are bicyclic, sulfur-containing, rigid structures, which, due to their differentiable functional groups, allow easy manipulations of the molecular architecture and can be used as veritable glycosyl scaffolds.