Mass spectrometry in structural and stereochemical problems. Part CCXX. Synthesis and mass spectra of 5α-cholest-8(9)- and 8(14)-en-7-ones

Abstract

5α-Cholest-8(14)-en-7-one (II) was prepared by a route known to produce authentic steroidal Δ⁸⁽¹⁴⁾-7-ketones, and the Δ⁸⁽⁹⁾-7-ketone (I) was obtained from a side product of this reaction. On the basis of chemical and spectroscopic evidence, it was shown that these samples are correctly formulated, whereas those reported earlier, by others, are not. Each of these enones undergoes a characteristic reaction in the mass spectrometer, and mechanisms for both diagnostically important processes are suggested.