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

Abstract

The characteristic mass spectral fragmentation patterns of the basic structure of the steroidal sapogenin, (2SR)-Sa-spirostan, have been elucidated through the preparation of analogs with deuterium labels at positions 1 1 , 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.

Antiprotozoal Compounds from Asparagus africanus

“…This was supported by the fragmentation pattern in the EIMS spectrum in which a major peak at m/z 139, and others at m/z 370, 328, 299, 126, and 115 all are indicative of a spiroketal moiety . In addition, the base peak m/z 328, the prominent peak at m/z 139, and the peak at m/z 126 indicate the absence of other substituents on ring F than the methyl group …”

Neochlorogenin, Neosolaspigenin, and Solaspigenin from Solanum torvum Leaves

“…The M+ was observed at mtz 448 and other important peaks at m/z 363, 345, 327, 289, 271, and 253. The peak at m!z 363 is characteristic of 23-hydroxyspirostanes (8).…”

Zur Prins‐Reaktion von Lumihecogeninacetat

“…Welzel, B. Janssen und H. Duddeck 19). -MS19): m / z ('70) = 566 (3, M i ) ; 487 (100); 457 (18); 373 (12); 355 (18); 139 (28, b ) ; 126 (67, I ) ; 115 (15, n). C2,H4306Br (567.5) Ber.…”