Silver bullet: A methodology for stereoselectivesynthesis of polysubstituted tetrahydronaphthols catalyzed by [Ag+]/NPO has been developed. The reactions proceeded through an unprecedented [4+2] cyclization of 2‐(2‐formylphenyl)ethanone and an alkene, in both inter‐ and intramolecular fashion. NPO=pyridine N‐oxide.