Abstract The sirup obtained as a by-product with β-1-C-phenyl-2-acetamido-2-deoxy-3,4,6-tri-O-acetyl-d-glucopyranoside by the action of phenylmagnesium bromide on acetobromo-d-glucosamine hydrobromide has been deacetylated and chromatographed to yield the α-anomer. Several α-derivatives have been described, among which, α-1-C-(p-nitrophenyl)-2-dichloroacetamido-2-deoxy-d-glucopyranoside which is a chloramphenicol derivative showed no antibiotic activities. The application of Hudson’s rules of isorotation to the anomeric compounds in this series is discussed.