Highly Stereoselective Intramolecular SN2′ Cyclization Yielding Chiral ­Oxazolidin-2-ones: General Route to α-Hydroxy-β-amino Acids

Intramolecular nucleophilic attack onto allylsulfonates promoted by silica gel acting as an acid catalyst provides expedient stereoselective access to 4,5-difunctionalized oxazolidin-2-ones. Precursors were prepared efficiently from enantiopure α-amino acids and subsequent manipulation of the oxazolidin-2-ones yielded enantiopure α-hydroxy-β-amino acids.