Synthesis of Spirocyclic Cyclopropyl Glycosyl-1-phosphate Analogues.

A general methodology allowing the preparation of phosphonylated 1-spirocyclopropyl analogues of glycosyl-1-phosphates is reported. The scope of this reaction has been assessed using various exo -glycals easily obtained from the corresponding pyranoses and furanoses. The cyclopropanation was found to be stereospecific, and the cis/trans selectivity only depends on the E / Z configuration of the starting exo -glycal. The four possible isomers of spirocyclopropyl ribose-1-phosphonate could thus be prepared in a controlled manner, protected and deprotected.