Cr-Mediated Stereoselective Synthesis of α,β-Unsaturated Esters and Amides

Significance

A novel chromium-mediated synthesis of carbohydrate-based polysubstituted (E)-α,β-unsaturated carboxylic esters and amides starting from a range of sugar aldehydes and α,α-dichlorocarbonyls is disclosed. In a mechanistic proposal, a sequential chromium-promoted aldol reaction and stereoselective β-elimination are the key steps of this transformation.