35730-27-9Relevant academic research and scientific papers
Ketene-Ketene interconversion. 6-Carbonylcyclohexa-2,4-dienone-hepta-1,2,4, 6-tetraene-1,7-dione-6-oxocyclohexa-2,4-dienylidene and wolff rearrangement to fulven-6-one
Koch, Rainer,Blanch, Rodney J.,Wentrup, Curt
, p. 6978 - 6986 (2014/08/18)
6-Carbonylcyclohexa-2,4-dienone (1) has been generated by flash vacuum thermolysis (FVT) with Ar-matrix isolation of methyl salicylate (7), 2-phenylbenzo-1,3-dioxan-4-one (8), phthalic peranhydride (9), and benzofuran-2,3-dione (11) and also by matrix photolysis of 9, 11, and 2-diazocyclohepta-4,6-dien-1,3-dione (12). In each case, FVT above 600 °C results in decarbonylation of 1 and Wolff rearrangement to fulven-6-one (13) either concertedly or via open-shell singlet 6-oxocyclohexa-2,4-dienylidene (18). Ketenes 1 and 13 were characterized by IR spectroscopy. Photolysis of matrix-isolated 1 at 254 nm also results in the slow formation of 13. The sequential formation of ketenes 1 and 13 from 7 has also been monitored by FVT-mass spectrometry, and 13 has been trapped with MeOH to afford methyl 1,3-cyclopentadiene-1- and -2-carboxylates 15 and 16. FVT of methyl salicylate-1-13C 7a revealed a deep-seated rearrangement of the 13C-labeled 1a to hepta-1,2,4,6-tetraen-1,7-dione (17a) by means of electrocyclic ring opening followed by a facile 1,5-H shift and recyclization prior to CO-elimination and ring contraction to 13C-labeled 13. The rearrangement mechanism is supported by M06-2X/6-311++G(d,p) calculations, which predict feasible barriers for the FVT rearrangements and confirm the observed labeling pattern in the isolated methyl salicylate 7a/7b and methyl cyclopentadienecarboxylates 20 and 21 resulting from trapping of 13 with MeOH.
Reactions retrodieniques XX. Synthese et thermolyse eclair de bis-adduits de Diels-Alder : creation d'une triple liaison fonctionnalisee par double cycloreversion
Lasne, Marie-Claire,Ripoll, Jean-Louis
, p. 766 - 770 (2007/10/02)
La thermolyse eclair de bis-adduits de Diels-Alder appropries peut conduire a des alcynes fonctionnels.Cette reaction a ete testee sur les bis-adduits 1-3 du propiolate de methyle avec le cyclopentadiene, le furanne et l'anthracene respectivement et une double cycloreversion specifique en les composes de depart a ete obtenue a partir de 3.Une application a la mise en evidence de l'ethynol et de l'ethynamine a ete tentee avec la synthese et la thermolyse eclair des bis-adduits 9 et 10.Alors que seuls les tautomeres stables, cetene ou acetonitrile, ont ete detectes par RMN ou spectrometrie de masse, l'analyse par IR a basse temperature montre de plus des bandes faibles disparaissant a - 150 deg C et qui pourraient etre respectivement attribuees a l'ethynol (2230 cm-1) et a l'ethynamine (2160 cm-1).
Synthesis of some 1,2-Dihalogenonorbornanes
Krebs, Ernst-Peter,Keese, Reinhart
, p. 2029 - 2041 (2007/10/02)
The synthesis of 1,2exo-dibromo-norbornane as well as the preparation of the configurational isomers of 2-bromo-1-iodo- and 2-chloro-1-iodo-norbornane are described.
