3-O-Methyl-1-isomangostin

In the title xanthone derivative [systematic name: 9-hy­droxy-5,10-dimeth­oxy-2,2-dimethyl-11-(3-methyl­but-2-en-1-yl)-2,3,4,12-tetra­hydro-1,7-dioxatetra­phen-12-one], C(25)H(28)O(6), the xanthone ring system is roughly planar, with an r.m.s. deviation of 0.1038 (1) Å. The chromane ring is in a half-chair conformation and the 3-methyl­but-2-enyl substituent is axially attached with an (+)-anti­clinal conformation. Two weak intra­molecular C—H⋯O inter­actions generate two S(6) ring motifs. In the crystal, mol­ecules are linked into ribbons along the c axis by O—H⋯O and weak C—H⋯O hydrogen bonds. A π–π inter­action, with a centroid–centroid distance of 3.5413 (8) Å, is also observed.