(E)-2-Methyl-3-phenyl­selanyl-4-(phenyl­sulfin­yl)oct-3-en-2-ol

In the title compound, C₂₁H₂₆O₂SSe, the S atom adopts a pyramidal geometry (bond-angle sum = 304°) and the n-butyl chain shows an extended conformation. An intra­molecular C—H...O hydrogen bond closes an S(8) ring. In the crystal, inversion dimers are formed with molecules linked by pairs of O—H...O=S hydrogen bonds, generating R₂²(14) loops. Weak C—H...O inter­actions also occur.