title: (-)-2-(1,2,3,4,4a,5,6,7,8,8aalpha-Decahydro-4abeta,8alpha-dimethyl-7-oxo-2beta-naphthyl)propionic acid: catemeric hydrogen bonding in a bicyclic sesquiterpenoid zeta-keto acid.
abstract: In the title compound, C(15)H(24)O(3), derived from a naturally occurring sesquiterpenoid, the asymmetric unit consists of two molecules differing by 167.4 (8) degrees in the rotational conformation of the carboxyl group. Each molecule aggregates separately with its own type as carboxyl-to-ketone hydrogen-bonding catemers [O...O = 2.715 (6) and 2.772 (6) A, and O-H...O = 169 and 168 degrees ]. This generates two crystallographically independent single-strand hydrogen-bonding helices passing through the cell in the b direction, with opposite end-to-end orientations. One intermolecular C-H...O=C close contact exists for the carboxyl group of one of the molecules. The structure is isostructural with that of a closely related unsaturated keto acid reported previously.
authors.affiliation: Carl A Olson Memorial Laboratories, Department of Chemistry, Rutgers University, Newark, NJ 07102, USA.
authors.forename: Hugh W
authors.initials: HW
authors.lastname: Thompson
authors.forename: Roger A
authors.initials: RA
authors.lastname: Lalancette
mesh_terms: D018360:Crystallography, X-Ray; D006860:Hydrogen Bonding; D007651:Keto Acids / Q000737:chemistry*; D015394:Molecular Structure; D011422:Propionates / Q000737:chemistry*; D012717:Sesquiterpenes / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D007651:Keto Acids; D011422:Propionates; D012717:Sesquiterpenes; C029658:propionic acid