4,4′-[(2R*,3R*,4R*,5R*)-3,4-Dimethyl­tetra­hydro­furan-2,5-di­yl]diphenol

The title mol­ecule, C(18)H(20)O(3), is a furan­oid lignan extracted from the leaves of Larrea tridentata. The relative absolute configuration for the four chiral centers was established, showing that this compound is 4-epi-larreatricin, which has been previously reported in the literature. The mol­ecule displays noncrystallographic C (2) symmetry, with the methyl and phenol substituents alternating above and below the mean plane of the furan ring. The conformation of this ring is described by the pseudorotation phase angle P = 171.3° and the maximum out-of-plane pucker ν(m) = 37.7°. These parameters indicate that the furan ring adopts the same conformation as the ribose residues in B-DNA. The packing is dominated by inter­molecular O—H⋯O hydrogen bonds. The phenol hy­droxy groups form chains in the [110] direction and these chains inter­act via O—H⋯O(furan) contacts.