Mass spectrometry in structural and stereochemical problems–CXCIV: The mass spectrometric fragmentations of steroidal sapogenins

The characteristic mass spectral fragmentation patterns of the basic structure of the steroidal sapogenin, (25R)‐5α‐spirostan, have been elucidated through the preparation of analogs with deuterium labels at positions 11, 12, 14, 15, 16, 17, 20, 21, 23, 24, 25, 26 and 27. In addition, the effects of a change of stereochemistry at positions 14 and 20, of the introduction of oxygencontaining functionalities mostly in ring F, and of the incorporation of olefinic unsaturation have been determined through synthesis of many examples.