Theerythroandthreochiral C5methyl ketones (4) and (5), prepared from the (2S, 3R)-methyl diel (1b), were converted into the phenylsulfenimines (6) and (7), which, in turn, on reaction with allyl-magnesiutn bromide, yielded after acid hydrolysis and benzoylation, the diastereoisomeric C8-N-aminodiol derivatives (9) and (11), withthreostereochemistry relative to positions 4 and 5. Ozonolysis of (9) and (11) yielded thel-arabinoandl-xylo3-O-methyl branched aminodeoxysugar derivatives (13) and (15), respectively. Using diallylzinc as the reagent, the diastereoisomeric erythro products (8) and (10) were obtained. The latter materials gave thel-ribo-andl-lyxo-(lL-vancosamine) derivatives (12) and (14) upon oxonolysis. The1H and13C NMR spectra of the four isomeric aminodeoxysugar derivatives (12)—(15) were discussed.