title: Synthesis of a trans,syn,trans-dodecahydrophenanthrene via a bicyclic transannular Diels-Alder reaction: intermediate for the synthesis of fusidic acid.
abstract: While thermolysis of the macrobicyclic triene lactone 12 did not produce the expected bicyclic transannular Diels-Alder (BTADA) product 13, heating the corresponding ether 18 to 110 °C for 4 h afforded a quantitative yield of the desired cycloadduct 19, which could be easily reduced to the perhydrophenanthrene, an ABC ring analogue of fusidic acid 1. Theoretical calculations with hybrid density functional theory (B3LYP/6-31G(d)) help rationalize why the lactone does not cyclize whereas the ether does.
authors.affiliation: Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive, Los Angeles, California 90095-1569, USA. jung@chem.ucla.edu
authors.forename: Michael E
authors.initials: ME
authors.lastname: Jung
authors.forename: Ting-Hu
authors.initials: TH
authors.lastname: Zhang
authors.forename: Rebecca M
authors.initials: RM
authors.lastname: Lui
authors.forename: Osvaldo
authors.initials: O
authors.lastname: Gutierrez
authors.forename: K N
authors.initials: KN
authors.lastname: Houk
mesh_terms: D018360:Crystallography, X-Ray; D005672:Fusidic Acid / Q000138:chemical synthesis* / Q000737:chemistry; D008958:Models, Molecular; D056004:Molecular Dynamics Simulation; D015394:Molecular Structure; D010616:Phenanthrenes / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D010616:Phenanthrenes; D005672:Fusidic Acid