Chemoselective glycosylation of carboxylic acid with glycosyl ortho-hexynylbenzoates as donors

The gold(I)-catalyzed glycosylation of acid alcohols with glycosyl ortho-hexynylbenzoates in the presence of BF3·Et2O and DBU provided the corresponding ester glycosides chemoselectively in high yield; while with DTBP as an additive instead, orthoester formation with the alcohol was effected selectively.