Building carbohydrates on the dioxanone scaffold: stereoselective synthesis of d-glycero-d-manno-2-octulose

The title compound has been synthesized via two proline-catalyzed aldol addition reactions of 2,2-dialkyl-1,3-dioxan-5-ones: the first addition to 1,3-dithiane-2-carboxaldehyde, followed by reduction to the corresponding diol, protection of the OH groups and dithiane hydrolysis afforded a protected d-ribose that was used in the second aldol addition reaction.