
%0 Journal Article
%A Collins, DJ 
%A Hobbs, JJ 
%A Sternhell, S 
%T The Stereochemistry of Rings A and B in 6-Substituted &#916;<sup>4</sup>-3-Oxosteroids: A Study of H<sup>1</sup> Allylic Spin-Spin Coupling in Systems with Defined Geometry
%J Australian Journal of Chemistry
%D 1963/12/01
%V 16
%N 6
%P 1030-1041
%K 
%R https://doi.org/10.1071/CH9631030
%U https://www.publish.csiro.au/paper/CH9631030 
%X The preparation of some 6-substituted A4-3-oxosteroids is described. As previously announced, the stereochemistry at the 6-position, which is of importance in connection with biological activity, may be deduced from examination of the N.M.R. signal due to the vinylic proton at C4 which appears as a singlet (WH = 1.5 - 1.8 c/s)in the 6&#946;-substituted series and as a doublet (J = 1.6 - 1.8 c/s) in the 6&#945;-substituted series. The general dependence of the allylic coupling constants on stereochemistry is examined and an empirical angular relation shown to exist, with the coupling constant at a maximum when the angle subtended between the allylic and vinylic protons is 90° and at a minimum when it is 0 or 180°. Theoretical implications are briefly considered. 
