Salt effects on the conformational behavior of 5-substituted 1,3-dioxanes
E. Juaristi**, G. A. Rosquete-Pina, M. V�zquez-Hern�ndez, and A. J.
Mota
Departamento de Química, Centro de Investigación
y de Estudios Avanzados del Instituto Politécnico Nacional,
Apartado Postal 14-740, 07000-México, D. F., México
Abstract: Since their introduction by E. L. Eliel
nearly four decades ago, derivatives of 1,3-dioxane have proved useful
in conformational analysis. Examples are discussed, where 5-polar substituents
permit the evaluation of fundamental phenomena such as attractive and
repulsive gauche effects, electrostatic interactions, and stereoelectronic
effects. By the same token, 2-substituted 1,3-dioxanes, 1,3-dithianes,
and 1,3-oxathianes are useful frameworks for the study of the anomeric
effect and the associated structural and spectroscopic manifestations,
such as the so-called Perlin effects. In view of the varied and essential
involvement of metal ions and inorganic salts in biological processes,
5-substituted 1,3-dioxanes are presently being examined in the presence
of Li+, Na+, K+, Ag+, Mg2+,
Ca2+, Ba2+, and other cations, with the aim to
increase the understanding of biomolecular properties in vivo.
*Plenary lectures presented at the 16th International
Conference on Physical Organic Chemistry (ICPOC-16): Structure
and Mechanism in Organic Chemistry, San Diego, California,
USA, 4�9 August 2002. Other presentations are published in this issue,
pp. 541�630.
**Corresponding author