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Characterization and chemistry of vinylketene prepared by flash vacuum pyrolysis. Study of the flash vacuum pyrolysis of hydroaromatic compounds: 5,8-diphenyltetralin and the parent and substituted 5,6,11,12-tetrahydrodibenzo(a,e)cyclooctenes

Thesis/Dissertation ·
OSTI ID:5676446
Flash vacuum pyrolysis (FVP) has been used successfully to discover some novel thermal reactions. These provide new insights into some fundamental chemistry. Benzocyclobutene and its (4 + 4) dimer, 1,5-dibenzocyclooctadiene were found to give anthracene as a major product. The similarity of the product mixtures is taken as evidence that essentially the same mechanism is operating in both cases. By labeling studies, the (4 + 2) spirodimer appears to be an intermediate. The fragmentation by which the spirodimer is thought to give anthracene is new and analogous to the retroene reaction. The proposed mechanism lends new insight into the mechanism of the pyrolytic formation of benzene and higher aromatics. Vinylketene, prepared by FVP, was characterized by low-temperature /sup 1/H- and /sup 13/C-NMR spectroscopy. It was found to dimerize by a novel (4 + 2) cyclo-addition reaction. The resulting delta-lactone was isomerized to a mixture of sibirinone and 6-allyl-..cap alpha..-pyrone. Acid-catalyzed isomerization gave primarily sibirinone (9:1 mole ratio). When vinylketene was mixed with cyclopentadiene, the (2 + 2) cycloadduct was formed with high regio- and stereospecificity. The (2 + 2) cycloadduct was isomerized to bicyclo(4.2.1)nona-3,7-dien-2-one. An attempt to determine the effect of surface catalysis in FVP is described. The synthesis of 5,8-diphenyltetralin was described. Comparison of the pyrolysis of this compound to that of the parent compound tetralin was not possible since the thermal chemistry of the two compounds is so different.
DOE Contract Number:
W-7405-ENG-82
OSTI ID:
5676446
Country of Publication:
United States
Language:
English

Similar Records

Characterization and chemistry of vinylketene prepared by flash vacuum pyrolysis. Study of the flash vacuum pyrolysis of hydraomatic compounds: 5,8-diphenyltetralin and the parent and substituted 5,6,11,12-tetrahydrodibenzo(a,e)cyclooctenes
Technical Report · Sat Dec 31 23:00:00 EST 1983 · OSTI ID:5305954
Characterization and chemistry of vinylketene prepared by flash vacuum pyrolysis. Study of the flash vacuum pyrolysis of hydroaromatic compounds: 5,8-diphenyltetralin and the parent and substituted 5,6,11,12-tetrahydrodibenzo(a,e)cyclooctenes. Revision 1
Technical Report · Sat Dec 31 23:00:00 EST 1983 · OSTI ID:6950260
Gas-phase intramolecular Diels-Alder reactions of 2,3-dimethylene-2,3-dihydrofurans. II. Formation of anthracene and other polycyclic aromatic compounds in the pyrolysis of 1,5-bidenzocyclooctadienes and related compounds. III. Formation of 9-methylanthracene and anthracene in the pyrolysis of 5,6,11,12-tetrahydrodibenzo(A,E)cyclooctene and other related compounds. IV. Preparation of cyclopentadienones by flash vacuum pyrolysis and their dimerization and intramolecular reactions
Thesis/Dissertation · Wed Dec 31 23:00:00 EST 1986 · OSTI ID:5638148

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400301* -- Organic Chemistry-- Chemical & Physicochemical Properties-- (-1987)
400800 -- Combustion
Pyrolysis
& High-Temperature Chemistry
ALKYL RADICALS
AROMATICS
BARYONS
CARBON 13
CARBON ISOTOPES
CHEMICAL REACTIONS
DECOMPOSITION
ELEMENTARY PARTICLES
EVEN-ODD NUCLEI
FERMIONS
HADRONS
HYDROCARBONS
ISOTOPES
KETENES
LIGHT NUCLEI
NMR SPECTRA
NUCLEI
NUCLEONS
ORGANIC COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
PROTONS
PYROLYSIS
RADICALS
SPECTRA
STABLE ISOTOPES
TETRALIN
THERMOCHEMICAL PROCESSES
VACUUM SYSTEMS
VINYL RADICALS