Resolution of 2,3-Dideoxy-DL-2-Enopyranos-4-Uloses Via Chromatographic Separation of their Diastereomeric O-tert-Butyloxycarbonyl-L-Alanyl Esters. A Convenient Synthesis of L- and D-Aculose

A simple and effective procedure for the resolution of 2,3-dideoxy-DL-2-enopyranos-4-uloses is presented. This procedure is based on column chromatographic separation of their diastereomeric O-(N-tert-butyloxycarbonyl)-L-alanyl esters, followed by mild acidic cleavage of the ester function. L-Aculose, 2,3,6-trideoxy-L-glycero-hex-2-enopyranos-4-ulose, is also prepared in satisfactory yield.