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 · Thu Jan 01 04:00:00 EST 1987

OSTI ID:5638148

Lee, S K

The intramolecular Diels-Alder reactions of 2,3-dimethylene-2,3-dihydrofurans have been investigated through the pyrolysis of 2-alkenyl-3-furylmethyl benzoates. Under flash vacuum pyrolysis (FVP) conditions each of the 2,3-dimethylene-2,3-dihydrofurans can undergo an intramolecular Diels-Alder reaction or 1,5-hydrogen shift to give the corresponding tricycles 4c,t, 5c,t, and 6c,t and 1,5-hydrogen shift products 36c,t and 37c,t. FVP of 1,5-dibenzocyclooctadienes containing heteroatoms and dibenzosuberanes gave the corresponding tricyclic compounds (benzodifuran (18), acridine (24), and anthracene) with exception of 6H, 11H-dibenzo(b,f)(1,4)-dioxocin (17). The FVP of 17 gave (2-hydroxybenzyl)-o-benzaldehyde (28) as a major product. A mechanistic study of the regiospecific formation of 9-methyl-anthracene from the sealed tube pyrolysis the (4 + 4) dimer of o-xylylene (1) is presented. This study was carried out by pyrolyzing several possible precursors for 9-methylanthracene (e.g., 5,6-dihydrodibenzo(a,e)cyclooctene, di-o-tolylethane, and 5-methyldibenzosuberane). Sealed tube pyrolyses of dibenzosuberanes and dibenzosuberones were also carried out. A new method of preparing cyclopentadienones by the pyrolysis of cyclic diethers is presented. Cyclopentadienones including inden-2-one have been utilized in the synthesis of polycyclic compounds. The transient existence of these intermediates has also been proven by the isolation of polycyclic compounds.

• Research Organization: Iowa State Univ. of Science and Technology, Ames (USA)
• DOE Contract Number: W-7405-ENG-82
• OSTI ID: 5638148
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ALKENES
ANTHRACENE
AROMATICS
CHEMICAL PREPARATION
CHEMICAL REACTIONS
CONDENSED AROMATICS
DECOMPOSITION
DIELS-ALDER REACTION
DIENES
DIMERIZATION
FURANS
HETEROCYCLIC COMPOUNDS
HYDROCARBONS
ORGANIC COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
POLYCYCLIC AROMATIC HYDROCARBONS
POLYENES
POLYMERIZATION
PYROLYSIS
SYNTHESIS
THERMOCHEMICAL PROCESSES