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ZUM MECHANISMUS MASSENSPEKTROMETRISCHER FRAGMENTIERUNGSREAKTIONEN BEI A/B‐ CIS ‐ VERKNüPFTEN 3α‐HYDROXYSTEROIDEN MIT UND OHNE 11‐KETOGRUPPE
Author(s) -
Ende M.,
Spiteller G.
Publication year - 1975
Publication title -
organic mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 0030-493X
DOI - 10.1002/oms.1210100306
Subject(s) - chemistry , stereochemistry , ring (chemistry) , fragmentation (computing) , ethylene , mass spectrum , deuterium , cleavage (geology) , hydrogen atom , medicinal chemistry , ion , group (periodic table) , physics , catalysis , materials science , biochemistry , organic chemistry , computer science , operating system , quantum mechanics , fracture (geology) , composite material
Mass spectra of steroids containing a carbonyl group in position 11 and a 3α‐hydroxy group in a cis connected A/B ring system are characterised by very strong [M – 72] + · key ions and may therefore be clearly differentiated from the spectra of their isomers. The mechanism of this fragmentation reaction was investigated by deuterium labelling and the DADI technique. The 3α‐hydroxy group is eliminated together with the 9α‐H atom. Next a hydrogen atom is transferred from the A ring to the B/C/D ring system. This causes the cleavage of the C‐3C‐4 bond and expulsion of C atoms 1 to 4 as butadiene. In 3α‐hydroxy‐5α‐androstanes possessing no 11‐keto group an analogous [M – 18] + . fragment is fromed, followed by the elimination of ethylene originating mostly from C‐1 and C‐2.