title: (+/-)-3-Ethyl-2-methyl-4-oxocyclohexanecarboxylic acid: catemeric hydrogen bonding in a cyclic delta-keto acid.
abstract: In the title compound, C(10)H(16)O(3), the two molecules of the asymmetric unit form acid-to-ketone hydrogen-bonded chains. The two species differ only very slightly and are related by a pseudo-center, so that the apparent translational relationship among the units of the hydrogen-bonded chain is actually a pseudo-translation, with the molecules alternating in type. Two counterdirectional pairs of chains proceed through each cell [O.O = 2.743 (2) and 2.683 (2) A, and O-H.O = 171 (3) and 157 (3) degrees ]. Three intermolecular C-H.O close contacts were found, involving all three O atoms of one of the molecules.
authors.affiliation: Carl A. Olson Memorial Laboratories, Department of Chemistry, Rutgers University, Newark, NJ 07102, USA.
authors.forename: Mark
authors.initials: M
authors.lastname: Davison
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Kikolski
authors.forename: Roger A
authors.initials: RA
authors.lastname: Lalancette
authors.forename: Hugh W
authors.initials: HW
authors.lastname: Thompson