Molecular and crystal structure of selected compounds containing 8,11-dioxa[4.3.3]propellane moiety

► Propellane: tricyclic compound with elongated conjoining bond common for three rings. ► Conformation of propellane molecule is imposed by the rigidity of the whole molecule. ► Boat conformation of cyclohexene ring is the most stable one for such propellanes. ► Tetrahydrofurane rings adopt the envelope conformation with a low inversion barrier. ► Low inversion barrier of tetrahydrofurane rings caused disorder in crystal structure.