Triangulanes are named according to the rules of systematic nomenclature for spiro compounds.[2] The pattern of their common names is "[n]triangulane", where n is the number of cyclopropane units. The simplest such chemical, [2]triangulane, is named spiro[2.2]pentane by systematic nomenclature. Chains consisting of four or more cyclopropane units—[4]triangulane and higher—can form chiral helices.[1] This property is unusual for a molecule that contains no stereogenic atoms; the chiral nature is due to restricted mobility of the chain ends analogous to helicene molecules.
The rings can form a branched or cyclic patterns. For example, [3]rotane is a branched [4]triangulane; it consists of one additional cyclopropane attached to the central ring of a [3]triangulane chain.[3]
References
^ abZefirov, Nikolai S.; Kozhushkov, Serge I.; Kuznetsova, T. S.; Kokoreva, O. V.; Lukin, K. A.; Ugrak, B. I.; Tratch, Serge S. (1990). "Triangulanes: stereoisomerism and general method of synthesis". J. Am. Chem. Soc. 112 (21): 7702–7707. doi:10.1021/ja00177a034.