title: 3-Oxo-5beta-24-norcholanic acid: acid-to-acid hydrogen-bonding catemers employing the rare anti carboxyl conformation in the aggregation of a steroid keto acid.
abstract: The title ketocarboxylic acid [systematic name: (5R,8R,9S,10S,13R,14S,17R,20R)-3-oxo-24-norcholanic acid], C(23)H(36)O(3), forms acid-to-acid hydrogen-bonding chains [O...O = 2.620 (2) A and O-H...O = 163 (3) degrees ] in which all carboxyl groups adopt the rare anti conformation, while the ketone group does not participate in the hydrogen bonding. The occurrence and energetics of this conformation are discussed. One intermolecular C-H...O close contact exists, which plays a role in stabilizing the hydrogen-bonding arrangement.
authors.affiliation: Carl A. Olson Memorial Laboratories, Department of Chemistry, Rutgers University, Newark, NJ 07102, USA.
authors.forename: Marisa
authors.initials: M
authors.lastname: DeVita Dufort
authors.forename: Mark
authors.initials: M
authors.lastname: Davison
authors.forename: Roger A
authors.initials: RA
authors.lastname: Lalancette
authors.forename: Hugh W
authors.initials: HW
authors.lastname: Thompson