Collect. Czech. Chem. Commun. 1980, 45, 2985-2997

Splitting off of water from the molecular ions of steroidal cyclopropyl ketones

Alexander Kasal and Antonín Trka

Institute of Organic Chemistry and Biochemistry, Czechoslovak Academy of Sciences, 166 10 Prague 6


Mass spectra of 14 steroids containing a cyclopropane ring in the vicinity of a keto group were measured and the signals of the ions [M-H2O]+, [M-CH3]+ and [M-CO]+ were sought. Using models labelled selectively with deuterium it was shown that the water molecule, split off from the molecular ion of 3α,5-cyclo-5α-cholestan-6-one (I) is formed from the hydrogen atoms located in the positions 2β and 9α.