The reaction of (ortho-acetalaryl)arylmethanols with various phosphines PR¹R²R³ (R¹ = R² = R³ = Ph; R¹ = R² = Ph, R³ = Me and R¹ = R² = Me, R³ = Ph) under acidic conditions (e.g., HCl, HBF₄, TsOH) unexpectedly led to the formation of (10-hydroxy-9,10-dihydroanthr-9-yl)phosphonium salts instead of the corresponding anthryl phosphonium salts. The cyclization occurred according to the Friedel–Crafts mechanism but without the usually observed Bradsher dehydration, giving cyclic products in the form of cis/trans isomers and their conformers. In case of electron-rich and less-hindered dimethylphenylphosphine, all four stereoisomers were recorded in ³¹P{¹H} NMR spectra, while for the other phosphines, only the two most stable cis/trans stereoisomers were detected. This study was supported by DFT and NCI calculations in combination with FT-IR analysis.