ICl‐Induced Intramolecular Electrophilic Cyclization of 1‐[4′‐Methoxy(1,1′‐biphenyl)2‐yl]alkynones—A Facile Approach to Spiroconjugated Molecules

Spiro compounds: An iodine monochloride-induced intramolecular cyclization of 1-[4'-methoxy(1,1'-biphenyl)2-yl]alkynones has been developed (see scheme). An electrophilic iodocyclization selectively takes place at the ipso position (versus the ortho electrophilic aromatic substitution) to afford 4'H-spiro(cyclohexa[2,5]diene-1,1'-naphthalene)-4,4'-diones, a new group of spiroconjugated compounds.