Planarization of Tetracoordinate Carbon Atom. Synthesis of 13-oxa-14-oxo-pentacyclo [5.5.2.1.04,15010,15]pentadecane,a bridged ‘tetraquinacane’ preliminary communication

Structural aspects of planoid deformation of tetracoordinate carbon atom, particularly those in annulenes with central carbon atom are discussed. [12] Annulene 11 with central carbon atom is proposed as compound with strong planoid deformation around the internal carbon centre. The synthesis of a saturated precursor 15 is described.