Direct asymmetric organocatalytic de novo synthesis of carbohydrates

A biomimetic organocatalytic asymmetric synthesis of carbohydrates can be accomplished by a proline catalyzed aldol reaction with the dihydroxyacetone equivalent 2,2-dimethyl-1,3-dioxan-5-one and various aldehydes. The biomimetic C3+Cn strategy directly generates selectively protected carbohydrates in one step, which can be easily deprotected. Additionally, the stereoselective reduction of the keto functions allows a direct entry to different aldopentoses.