15577-76-1;2,7-Methano-1H-cyclopropa[b]naphthalene,1a,2,7,7a-tetrahydro-(1a.alpha.,2.beta.,7.beta.,7a.alpha.)-;2,7-Methano-1H-cyclopropa(b)naphthalene,1a,2,7,7a-tetrahydro-(1aalpha,2beta,7beta,7aalpha)-