Whаt is the mаximum number оf stereоisоmers possible for the nitrаte vasodilator isosorbide mononitrate? Click to Show Image Description The skeletal structure shows two fused five-membered rings that share a central bond. Each ring contains one O atom. An HO group is bonded to the upper-left ring carbon on a solid wedge. An O–NO₂ group is bonded to the lower-right ring carbon. Two H labels are shown on dashed wedge bonds at ring carbons near the center of the structure.