ISSN:
0009-2940
Keywords:
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Description / Table of Contents:
Organosulfur Compounds, VIII. Formation of Thiophenes by Pyrolysis of Dihydrothiopyrans, Reactions of Diels-Alder Adducts from Thiofluorenone and 1,3-Butadienes under Heating and Electron-Impact ConditionsThiofluorenone (1) reacts with 2,3-dimethyl- and 2,3-diphenyl-1,3-butadienen to give the Diels-Alder adducts 2a and 2b respectively. The adducts 2a and 2b, thermally stable either in solution or in the solid, decompose under electron-impact conditions according to the Retro-Diels-Alder principle. The pyrolysis of the spiro-dihydrothiopyranes 2 gives the thiophenes 3 and 4. The constitution of the new compounds 2, 3 and 4 finds confirmation from their mass, 1H-and 13C-n.m.r. spectra.
Notes:
Aus Thiofluorenon (1) und 2,3-Dimethyl-bzw. 2,3-Diphenyl-1,3-butadien entstehen die Diels-Alder-Addukte 2a bzw. 2b, die thermisch nicht - weder in Lösung noch in Substanz -, wohl aber unter Elektronenstoß nach dem Retro-Diels-Alder-Prinzip zerfallen. Die Pyrolyse der Spiro-dihydrothiopyrane 2 in Substanz liefert die Thiophene 3 und 4. Die Konstitutionsermittlung der neuen Verbindungen 2, 3 und 4 beruht u. a. auf Massen-, 1H-NMR-und 13C-NMR-Spektren.
Additional Material:
2 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cber.19741070916
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