Conformations of some decahydroquino- lin-4-ols: Study by kinetics of chromic acid oxidation

Abstract

Some <em>2-</em>aryl<em>-trans-decahydroquinolin-</em>4<em>-</em>ones and 3-methyl- 2-aryl-<em>trans</em>-decahydroquinolin-4-ones have been subjected to sodium <em>n</em>-butanol, MPV and sodium borohydride reductions. The sodium borohydride reduction gives both the epimers, the sodium <em>n</em>-butanol reduction gives almost exclusively the equatonal alcohol (<em>ɑ</em>-form) and the MPV reduction the axial alcohol (<em>&beta;</em>-form). The second order rate constants for the oxidation of the epimeric 2-aryl-trallS-decahydroquinolin-4-ols and their 3-methyl and 1,3-dimethyl derivatives by chromic acid have been determined in acetic acid-water in the presence of perchloric acid at 30&deg;e. The rate constants reveal the steric environment of the hydroxy group in these alcohols. Introduction of methyl substituent in I and 3 positions of decahydroquinoline system results in the distortion of the heterocyclic ring from the regular chair conformation.