ent-7alpha,18-Hydroxykaur-16-ene ethanol solvate.

The ent-kaurene diterpene in the title compound, 7-epicandicandiol ethanol solvate, C20H32O2.C2H6O, was isolated from the aerial parts of Sideritis ozturkii Aytaç & Aksoy. The molecule has the usual conformation and stereochemistry found in related ent-kaurene derivatives. The methyl-substituted ring junction has a trans arrangement and the other junction is cis. The six-membered rings have chair or slightly distorted chair conformations and the five-membered ring has an envelope conformation. Intermolecular hydrogen bonds link the 7-epicandicandiol and ethanol molecules into two-dimensional networks, part of which comprise co-operative O-H...O-H...O-H... chains.