During oxidation of 2,3-epoxytetralene by DMSO in the presence of oxygen(1) beside the trans-2,3-tetralenediol, β-naphtol and 2,3-naphtalenediol a crystalline compound (m.p. 199°-200°C), identified as the unknown 3-hydroxy - 1,2-(2',3'-naphtoxy)-naphtalene I (Fig. 1)was obtained:The structure of this diether was determined by spectroscopic methods. The Uv spectrum with max 225.8 - 226.8 nm (log σ = 4.94), ma 279.5 -28035 nm (log σ = 3.88), max 336.5 nm (log σ 3.67) is quite similar to that of β -naphtol (2). Its IR spectrum (KBr) discs differs from that of β naphtol although absorptions due to similar structural fragments, like the intermolecular H-bond interactions of OH groups of aromatic rings (3370 - 3340 cm− 1and 3070 cm− 1) and a single aromatic hydrogen atom (815-810 cm− 1) are being observed.