1,6-Methanoannulene , 1,6-methanonaphthalene or homonaphthalene is a hydrocarbon with chemical formula C11H12.
It is analogous to cyclodecapentaene (annulene), but with two hydrogen atoms replaced by a transannular methylene bridge (-CH
2-). This compound is aromatic as judged from lack in bond length alternation by x-ray crystallography and a telltale diamagnetic ring current from NMR spectroscopy.
Its resonance energy is smaller than that of naphthalene.