relation: http://publicatio.bibl.u-szeged.hu/32470/ title: Fragmentation and intramolecular cyclization in cyclopentane‐4,5‐fused 2‐N‐phenyliminoperhydro‐1,3‐oxazines and related thiazines under electron impact ionization creator: Oksman Pentti creator: Pihlaja Kalevi creator: Fülöp Ferenc creator: Bernáth Gábor subject: 01.04. Kémiai tudományok subject: 01.06. Biológiai tudományok description: The influence of cyclopentane fusion on the fragmentation behaviour of 1,3-oxazines and related thiazines was studied. The differences observed in the rearrangement reactions between the hydrogen atom at the ortho position of the aromatic ring and one of the hetero atoms in the cyclohexane ring were also investigated. These rearrangements occur if the cyclohexane ring contains an electrophilic atom and the carbon atom next to it is substituted by a benzyl or arylamino group. The compounds examined were cis and trans isomers of the title compounds substituted with methyl and benzyl (in the latter case only the cis isomers) on the ring nitrogen. All the compounds exhibited a large [M - H]+ ion peak which decreased with increasing size of the substituent. This indicates an intramolecular cyclization prior to further fragmentation of the molecule. Methyl substitution seems to change the character of this intramolecular cyclization. The main routes of fragmentation resemble those of the cyclohexane-fused analogues more than those of the corresponding 5,6-fused compounds. The stereoisomers fragment so similarly that they cannot be distinguished from each other, except in the case of methyl substituted oxazines. date: 1995 type: Folyóiratcikk type: PeerReviewed format: text identifier: http://publicatio.bibl.u-szeged.hu/32470/1/aok_klny_164_95.pdf identifier: Oksman Pentti; Pihlaja Kalevi; Fülöp Ferenc; Bernáth Gábor: Fragmentation and intramolecular cyclization in cyclopentane‐4,5‐fused 2‐N‐phenyliminoperhydro‐1,3‐oxazines and related thiazines under electron impact ionization. RAPID COMMUNICATIONS IN MASS SPECTROMETRY, 9 (7). pp. 615-624. ISSN 0951-4198 (1995) identifier: doi:10.1002/rcm.1290090716 relation: https://doi.org/10.1002/rcm.1290090716 relation: 27996 language: eng relation: info:eu-repo/semantics/altIdentifier/doi/10.1002/rcm.1290090716 rights: info:eu-repo/semantics/restrictedAccess