Efficient methods of preparation of disubstituted exo-glycals by palladium cross-coupling reaction on the readily available dibromo exo-glycal and methoxycarbonyl exo-glycal have been developed. Hydrogenation of these new monosubstituted and disubstituted exo-glycals proceeded with a high stereocontrol and led to original C-glycosyl compounds.
Efficient methods for functionalization of readily available exo-glycals have been developed. Sequential palladium-catalysed cross-coupling of dibromo-substituted exo-glycals was first explored and allowed the formation of new disubstituted exo-glycals as single stereoisomers. Bromination of furano- and pyrano-methoxycarbonyl-exo-glycals led to a new series of monobrominated derivatives. These vinylic