35 research outputs found
The use of onβline H/D exchange for the investigation of alcohols and carbonyl compounds by reaction gas chromatography/mass spectrometry
[No abstract available
Mass spectrometry of derivatives and heterocyclic analogues of 9,10-dihydroanthracene
The fragmentation of derivatives of 9,10-dihydroanthracene and of its heterocyclic analogues containing atoms of O, S, N, P, Si, As, Se and Te at positions 9 and/or 10 is examined. The conditions reviewed are electron impact and chemical ionisation with recording of positive and negative ions. It has been shown that depending on its nature, the heteroatom may be eliminated together with substituents from the molecular ion or a substituent may be lost both as a radical and together with an additional H atom. The fragmentation of compounds in which the substituting groups are adjacent to the heteroatom is explained by the "peri-effect". The elimination of substituents from phenylene rings, at the meso position and at the heteroatom occurs in a similar manner to elimination in the corresponding aromatic derivatives. Β© 1991 The British Library
Preparation of Ξ±- and Ξ³-(Ξ±-furyl)pyridines
Mixtures of isomeric alkyl-substituted (in the pyridine ring) Ξ±- and Ξ³-(Ξ±-furyl)-pyridines were obtained in up to βΌ40% yields by condensation of furfural and ammonia with several aliphatic ketones and aldehydes (at 370-380 Β°C with a cadmium calcium phosphate catalyst). The dependence of the yields and structures of the corresponding isomers on the structure of the starting carbonyl compound was examined. Data from the PMR and mass spectra were used to prove the structures of the pyridine bases obtained. Β© 1981 Plenum Publishing Corporation