Conformational analysis of the 4a-methyl octahydrophenanthrene system. A spectroscopic and theoretical approach.

VILA, ALEJANDRO J.; SPANEVELLO, R. A.; OLIVIERI, A. C.; GONZÁLEZ SIERRA, M.; MCCHESNEY, J. D.

TETRAHEDRON

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 1989 vol. 45 p. 4951 - 4960

0040-4020

Solution low temperature 1H and 13C NMR experiments were run for the cis 4a-Methyl Octahydrophenanthrene hydrocarbon 1b, together with force-field and semiempirical MO calculations, which allow to predict its conformational preferences, and to calculate the kinetic parameters for this equilibrium. The synthesis and spectroscopic analysis of related rigid models (1a and 7) and of a series of configurationally defined 4a-Methyl Octahydrophenanthrols (9a to 13c) confirmed those findings and allowed some empirical rules to be drawn for predicting the stereo-chemistry, as well as the preferred conformation adopted by substituted 4a-Methyl octahydrophenanthrenes.