AbstractThe syntheses of the new hydrocarbons trimethylenetriasterane12, trispirocyclopropanetriasterane3, trispirocyclopropanenortricyclane4, and of the trispirocyclopropanenorbornanes5, 6, and7are reported.12contains six vinylcyclopropane units rigidly held in an antiperiplanar (ap) conformation in aD3hsymmetric framework.3and4are the first model compounds with bicyclopropyl units rigidly fixed in ans‐trans(ap) conformation (Θ = 180°). Their PE spectra reveal that the interaction parameter βww= −1.73 eV for this arrangement is the same as that for