Steroid–acid colour reactions. Part II. Carbon-13 nuclear magnetic resonance and ultraviolet spectra of protonated androst-4-ene-3,17-dione, pregn-4-ene-3, 20-dione, and androst-4-ene-3,11,17-trione

Abstract

The ¹³C n.m.r. spectra of carbonium ions formed from the title steroids have been recorded. Basic sites on the same molecule are protonated independently but most charge is located on C-5. These spectra are compared with those of model compounds described in Part I. The u.v. spectra of these steroids in sulphuric acid are discussed in the light of data from the ¹³C n.m.r. spectra.