IN THE TITLE COMPOUND [SYSTEMATIC NAME: (1R,3S,5R,6S)-8-methyl-3-(4-methyl-phenyl-sulfon-yloxy)-8-aza-bicyclo-[3.2.1]octan-6-yl acetate], C(17)H(23)NO(5)S, the fused piperidine ring exists in a chair conformation with the N atom and one C atom displaced by 0.876 (2) and -0.460 (3) Å, respectively, on opposite sides of the mean plane defined by the other four atoms. The fused pyrrolidine ring adopts an envelope conformation with the N atom deviating by 0.644 (3) Å from the mean plane of the other four atoms.