
TY  - JOUR
A1  - Collins, DJ 
A1  - Hobbs, JJ 
A1  - Sternhell, S 
T1  - 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
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1963
VL  - 16
IS  - 6
SP  - 1030
EP  - 1041
KW  - 
UR  - https://doi.org/10.1071/CH9631030 
N2  - 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. 
ER  -

