Synthesis of Ethyl 4-O-[4-(1,2,4-Oxadiazol-5-yl)phenyl]-α-D-mannopyranosides

The palladium-catalyzed reaction of 5-(4-hydroxyphenyl)-1,2,4-oxadiazoles with ethyl α-O-Δ2-glucopyranoside afforded ethyl 4-O-[4-(1,2,4-oxadiazol-5-yl)phenyl]-2,3-dideoxy-α-D-erythro-hex-2-enopyranosides. Bishydroxylation of the latter compounds gave the corresponding ethyl 4-O-[4-(1,2,4-oxadiazol-5-yl)phenyl]-α-Dmannopyranosides.