Select a problem from the list on the right. When the Show Problem button is pressed the IUPAC name of a compound will be shown in the information window. Draw the structural formula for this compound in the drawing window. Your answer is evaluated by the Check Answer button. If E/Z double bond isomers have hydrogen substituents it is not necessary to show them. Stereoisomers involving the configuration of ring substituents should be drawn using the wedge drawing tool.