title: Synthesis of, and structural assignments to the stereoisomers of bis (2,2')- and tris (2,2',2")-tetrahydrofurans: conformational features and ionic binding capacities of these gateway polycyclic networks.
abstract: Construction of the polytetrahydrofuranyl building blocks 6-10 from the common bissiloxyacetone precursor 11 is detailed. The approach is concise and, for the bis-(THF) pair, capitalizes on the full retention of configuration observed during the rhodium-promoted decarbonylation of aldehydes 18 and 19. The capability of the title compounds to associate with alkali metal ions in solution and the gas phase has demonstrated a preference for Li+ over Na+ and K+ in all cases, with 6 and 7 exhibiting somewhat higher binding selectivities than 8-10. The relative energy orderings of attainable conformations with the bis-THF and tris-THF series were explored computationally. The various envelope arrangements present in the individual THF units are shown to play a significant role alongside prevailing gauche interactions. The "gauche effect" is shown computationally not to be an accurate predictor of the lowest energy conformer.
authors.affiliation: Department of Chemistry and Biochemistry, University of California-Los Angeles, 405 Hilgard Avenue, Los Angeles, CA 90095-1569, USA.
authors.forename: Emel
authors.initials: E
authors.lastname: Adaligil
authors.forename: Barry D
authors.initials: BD
authors.lastname: Davis
authors.forename: David G
authors.initials: DG
authors.lastname: Hilmey
authors.forename: Young
authors.initials: Y
authors.lastname: Shen
authors.forename: Jason M
authors.initials: JM
authors.lastname: Spruell
authors.forename: Jennifer S
authors.initials: JS
authors.lastname: Brodbelt
authors.forename: K N
authors.initials: KN
authors.lastname: Houk
authors.forename: Leo A
authors.initials: LA
authors.lastname: Paquette