Chromogenic Reactions of Steroids with Strong Acids. IV. Specificity of the Kober Reaction

Abstract

The structural requirements were investigated for the Kober reaction of the steroidal molecules. On the basis of the data given by the ninety-four specimens of phenolic steroid or related substance (Table I), a compound will give the positive Kober reaction when the following features are wholly present in its molecule : 1) steroidal ring system, 2) phenolic ring A, 3) double bond or oxygen function in ring D, 4) angular methyl group at C₁₃, and 5) angular hydrogen atom.