All the possible types of the protopanaxatriol and protopanaxadiol glycosides, the major active yet extremely heterogeneous principles of ginsengs, could be accessed by the present sequence of transformations, including global removal of the sugar residues from the crude ginseng extracts and stepwise elaboration of the glycans onto the aglycone. In particular, intramolecular hydrogen-bonding and neutral conditions have enabled glycosylation of the highly sterically hindered and acid labile dammarane C20-OH.

Direct glycosylation of sugar oximes and HONHFmoc has been realized for the first time by using glycosyl ortho-hexynylbenzoates as donors under the catalysis of PPh3AuOTf, providing an effective approach to the synthesis of N–O linked saccharides, which are of great biological interest.

Using glycosyl trifluoroacetimidates as donors and nitromethane (or acetonitrile) as solvent, silylation and subsequent glycosylation were realized in a ‘one-pot’ procedure to provide the corresponding nucleosides derivatives in high yields.Figure options

All the possible types of the protopanaxatriol and protopanaxadiol glycosides, the major active yet extremely heterogeneous principles of ginsengs, could be accessed by the present sequence of transformations, including global removal of the sugar residues from the crude ginseng extracts and stepwise elaboration of the glycans onto the aglycone. In particular, intramolecular hydrogen-bonding and neutral conditions have enabled glycosylation of the highly sterically hindered and acid labile dammarane C20-OH.