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

• Published in: Journal of organic chemistry 2007-08, Vol.72 (16), p.6215-6223
• Main Authors: Adaligil, Emel, Davis, Barry D, Hilmey, David G, Shen, Young, Spruell, Jason M, Brodbelt, Jennifer S, Houk, K. N, Paquette, Leo A
• Format: Article
• Language: English
• Subjects: Chemistry; Exact sciences and technology; Heterocyclic compounds; Heterocyclic compounds with o, s, se, te hetero atom and condensed derivatives; Organic chemistry; Preparations and properties
• ISSN: 0022-3263; 1520-6904
• DOI: 10.1021/jo0708238

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.