A STEROID DERIVATIVE THAT CRYSTALLIZES WITH 3 MOLECULES IN THE ASYMMETRIC UNIT

Crystals of (20R,23S,24R)-5alpha-dinosteran-29-ol, C30H54-O, grow as b lades elongated in the direction of hydrogen-bonded chains of OH group s and thin in the direction of the 50 angstrom c axis. There are three independent molecules in the unit cell. Hydrogen-bonding requirements dictate that the OH group of each molecule be within a few angstroms of two other OH groups, but the bulk and shape of the rest of the mole cule preclude the three being related by crystallographic symmetry ele ments. The local symmetry of the hydrogen-bonded chains is approximate ly 3(1), but the only crystallographic symmetry parallel to the chains is translation. A survey of the Cambridge Structural Database shows t hat hydrocarbons with a single OH substituent commonly crystallize wit h more than one molecule in the asymmetric unit, or in space groups wi th three- or fourfold axes.