Herein we present a systematic study of l-rhamnosylation. The influence of protective groups, reactivity, solvents and glycosylation method, i.e. catalytic versus promoted glycosylation, are studied. It was found that the selectivity can be controlled to a large extend, by varying these parameters and hence the same donor can give both anomers. A reversal of the influence of the participating solvents is observed, and hence ethereal solvents increase the β selectivity, whereas nitrile solvents give almost exclusive α-selectively