title: trans-3-Ethyl-cis-2,6,6-trimethyl-4-oxocyclohexanecarboxylic acid: an intermediate in the synthesis of a highly potent estrogen.
abstract: The title compound, C(12)H(20)O(3), (IV), the ethyl ester of which is an intermediate in the synthesis of a compound reported to be highly estrogenic, has been prepared. After the initial steps reported for the synthesis of this ester intermediate were followed, it was converted into the crystalline acid, (IV), for X-ray analysis. It was verified that (IV) was racemic when prepared. X-ray analysis showed that anti-hydrogenation of the double bond had occurred in the synthesis, making the orientation of the carboxyl group cis to the 2-methyl group and trans to the 3-ethyl group. NMR spectroscopy showed that the stereochemistry of (IV) was identical with that of its ester precursor. While the earlier report did not note the stereochemistry of this ester, it pointed out that the estrogenic product derived from it possessed the opposite carboxyl-2-methyl orientation, i.e. trans, although no X-ray analysis was performed. In the light of these results and the importance of correlating biological activity with compound structure, the unequivocal characterization of the highly estrogenic compound is warranted.
authors.affiliation: Meyers Institute for Interdisciplinary Research in Organic and Medicinal Chemistry and the Department of Chemistry and Biochemistry, Southern Illinois University-4409, Carbondale, IL 62901, USA.
authors.forename: Songwen
authors.initials: S
authors.lastname: Xie
authors.forename: Yuqing
authors.initials: Y
authors.lastname: Hou
authors.forename: Cal Y
authors.initials: CY
authors.lastname: Meyers
authors.forename: Paul D
authors.initials: PD
authors.lastname: Robinson
mesh_terms: D003509:Cyclohexanecarboxylic Acids / Q000737:chemistry*; D045166:Estradiol Congeners / Q000737:chemistry*; D006860:Hydrogen Bonding; D008958:Models, Molecular; D008968:Molecular Conformation
chemical_list: C455521:3-ethyl-2,6,6-trimethyl-4-oxocyclohexanecarboxylic acid; D003509:Cyclohexanecarboxylic Acids; D045166:Estradiol Congeners