(2R,3S,4R,5R)-2-(tert-butyldimethylsilyloxymethyl)-6-ethoxy-3,4,5-trihydroxypiperidine-1-carboxylic acid benzyl ester

(2R,3R,4S,5S)-2-(tert-butyldimethylsilyloxymethyl)-6-ethoxy-3,4,5-trihydroxy-piperidine-1-carboxylic acid benzyl ester

(2R,3S)-2-(tert-butyldimethylsilyloxymethyl)-6-ethoxy-3-(4-nitro-benzoyloxy)-3,6-dihydro-2H-pyridine-1-carboxylic acid benzyl ester