Etude des fragmentations en spectrographie de masse de dithiannes-1,3 substitués en 2 par des groupements insaturés

The mass spectra of the title compounds always show an intense molecular ion. Some fissions involve loss of the ethylenic group, while others are related to cleavage of the dithiane ring, eventually followed by recyclizations involving the ethylenic chain stabilized by the resonance possibilities. If a phenyl group is present in the ethylenic chain, the spectra are modified by the formation of the very stable benzothiopyrylium ion.     

Apurinic DNA reactivity: Modelisation of apurinic DNA breakage with phenylhydrazine and formation of a pyrazole adduct

We have elucidated the exact mechanism of apurinic oligodeoxynucleotide d(Tp[AP]pT) cleavage by phenylhydrazine and shown that the final isolated product is in fact a 3-substituted derivative of 1-phenyl-pyrazole.     

Etude en RMN du carbone 13 de dicoumarols substitués

The ¹³C n.m.r. spectrum of the bridge substituted dicoumarols are interpreted in order to obtain structural information for quantitative structure-activity relationships. The results are in agreement with those obtained by ¹H n.m.r. These dicoumarols exhibit double restricted rotation around both bridge bonds.     

Structure électronique de quelques dérivés nitrés insaturés (méthode L.C.A.O. améliorée)

The electronic structure of Nitro-,p- andm-dinitro-,s-trinitro-benzene, nitro-ethylene, mono-, and dinitro-butadien have been calculated by an improved LCAO method.     

Rearrangement thermique des adduits du tetracyanoethylene de 2H-pyrannes

The addition of tetracyanotehylene to 2H-pyrans 1 results in a mixture of two isomeric adducts 6. The thermal decomposition of the compounds 6 gives rise to both a small percentage of the retro Diels-Alder, and a new mode of evolution leading to a mixture of furans (E+Z) 7. A detailed interpretation of the ¹³C spectra of the compounds 7 was established by comparison with the ¹³C spectra of 2,5-diphenylfuran and trans-stilbene. The structure 7 is confirmed by chemical degradation.