Conduramine B and a ‘condurithiol’, namely (1S,2S,3R,6R)-6-aminocyclohex-4-ene-1,2,3-triol and (1R,2S,3R,6R)-6-sulfanylcyclohex-4-ene-1,2,3-triol, have been prepared by the thermal rearrangement of an acetimidate and a dithiocarbonate, respectively. Both the amine and the thiol are putative inhibitors of β-xylosidases and, in order to mimic the natural substrate more closely, an N- and an S-pseudo-disaccharide have been prepared.