title: Steric control of alpha- and beta-alkylation of azulenone intermediates in a guanacastepene a synthesis.
abstract: The origins of different stereoselectivities observed experimentally in the alkylations of azulenone precursors in the guanacastepene A synthesis have been determined through density functional theory investigations. The optimized transition structures of methylation of two different guanacastepene A precursors show that steric effects, rather than torsional factors that often determine such stereoselectivities, dictate the preferred products observed.
authors.affiliation: Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569, USA.
authors.forename: Hao
authors.initials: H
authors.lastname: Wang
authors.forename: Karol
authors.initials: K
authors.lastname: Michalak
authors.forename: Michał
authors.initials: M
authors.lastname: Michalak
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Jiménez-Osés
authors.forename: J
authors.initials: J
authors.lastname: Wicha
authors.forename: K N
authors.initials: KN
authors.lastname: Houk
mesh_terms: D000478:Alkylation; D052176:Azulenes / Q000737:chemistry*; D004224:Diterpenes / Q000138:chemical synthesis / Q000737:chemistry; D015394:Molecular Structure; D013237:Stereoisomerism
chemical_list: D052176:Azulenes; D004224:Diterpenes; C409194:guanacastepene