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Electron impact mass spectrometry of polyannulated oxygen heterocycles with cyclic orthoester or acetal moieties
Author(s) -
Bravo Pierfrancesco,
Ticozzi Calimero,
Maccioni Anna Maria,
Traldi Piero
Publication year - 1987
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570240402
Subject(s) - chemistry , acetal , benzopyran , fragmentation (computing) , mass spectrometry , deuterium , orthoester , epoxy , bicyclic molecule , mass , stereochemistry , mass spectrum , organic chemistry , chromatography , physics , quantum mechanics , computer science , operating system
Abstract The mass spectrometric behaviour of the pairs of diastereoisomeric 3‐methyl‐ and 3‐phenyl‐substituted 3,11b‐epoxy‐2,3,4,5,5a,11b‐hexahydro‐5a‐hydroxyoxepino[3,2‐ c ][1]benzopyran‐6‐ones 5,6 and 7,8 and the pairs of diastereoisomeric 3‐methyl and 3‐phenyl substituted 3,11a‐epoxy‐2,3,4,5,5a,11a‐hexahydro‐5a‐hydroxyoxepino[2,3‐ b ][1]benzopyran‐6‐ones 9,10 and 11,12 has been studied in detail with the aid of exact mass measurements, B/E linked scans, collisional experiments and deuterium labelling. Characteristic ionic species for angularly annulated compounds 5‐8 and for linearly annulated ones 9‐12 have been found, thus allowing the structural assignment. No differences could be determined in the fragmentation patterns of the diastereoisomeric compounds.