Laser Raman spectra of some non-conjugated steroid olefins

Abstract

The Raman spectra of 27 steroids containing non-conjugated olefinic bonds in a range of positions have been measured for solid samples, for chloroform solutions and, in some cases, for carbon tetrachloride solutions, particular attention being paid to the 3 000–3 100 cm^–1 region (olefinic C–H stretching vibrations) and 1 600–1 700 cm^–1 region (olefinic double bond stretching vibrations). All the nuclear disubstituted olefins gave a band between 3 013 and 3 028 cm^–1. Some trisubstituted olefins gave a band between 3 035 and 3 040 cm^–1, but the others, like tetrasubstituted olefins, did not give any observable band in this region of the spectrum. All the olefins, including the tetrasubstituted olefins, gave strong bands between 1 632 and 1 676 cm^–1. The ranges of frequencies for the various double bond positions often overlap, but the ranges for Δ⁸-, Δ⁹⁽¹¹⁾-, and Δ^ll-olefins are different from those of other tetra-, tri-, and di-substituted double bonds respectively.