Locating the Cyclopentano Cousins of the Cucurbit[<i>n</i>]uril Family

The synthesis of the first family of fully substituted cucurbit­[n]­uril is discussed, and the structural features of precursor glycolurils are highlighted in their importance to achieving higher homologues. The members of the family, where n = 5–7, have been fully characterized, and increased binding affinities have been identified for dioxane in CyP6Q­[6] and adamantyl NH3+ in CyP7Q­[7]. A higher homologue is indicated but not conclusively identified.