Branched-chain conjugated dienepyranosides including vinyl phosphate esters were subjected to catalytic hydrogenation under different conditions. Heterogeneous catalysts led to isomerization products that were resistant to further hydrogenation. On the other hand, under homogeneous conditions, complete stereoselective hydrogenation was achieved. Methyl 2,4-dideoxy-3-O-diethoxyphosphoryl-4-C-[(methoxycarbonyl)methyl]-α-D-ribo-hexopyranoside (6b), a potential precursor of thromboxane analogs, was obtained.