Tuning effect of silyl protecting groups on the glycosylation reactivity of arabinofuranosyl thioglycosides.

The tuning effect of silyl protecting groups on the glycosylation reactivity of arabinofuranosyl phenyl thioglycoside donors Is presented. Silyl ethers on the 3-, 5-, and 3,5-positions of the arabinofuranose ring are found to have an arming effect on the donor reactivity, whereas the cyclic 3,5-acetal type protecting groups reduce the reactivity.