Efficient Synthesis of Orthogonally Protected Rare l-Hexoses and Derivatives

Abstract

Stereoselective preparations of protected rare sugars and derivatives, namely <sc>l</sc>-psicose, <sc>l</sc>-altritol, and <sc>l</sc>-talose have been achieved in 70, 44, and 18% yield, respectively, from an orthogonally protected <sc>l</sc>-glyceraldehyde derivative. The key step is the stereoselective proline-catalyzed aldol reaction of this aldehyde with dioxanone.