- An Observation on Carboxylation of 4H-Cyclopentaphenanthrene
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Photocarboxylation of 4H-cyclopentaphenanthrene by carbon dioxide in the presence of N,N-dimethylaniline in dimethyl sulfoxide afforded 8,9-dihydro-4H-cyclopentaphenanthrene-8- and 2-carboxyl acid, and 4H-cyclopentaphenanthrene-8-carboxylic acid.These acids were derived into methyl-4H-cyclopentaphenanthrenes.
- Minabe, Masahiro,Isozumi, Keisuke,Kawai, Ken-ichi,Yoshida, Masaaki
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p. 2063 - 2066
(2007/10/02)
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- FORCE FIELD-SCF CALCULATIONS ON CYCLOPROPENE INTERMEDIATES IN CARBENE REARRANGEMENTS. COMPARISON WITH EXPERIMENT
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Heats of formation and geometries of benzocyclopropene, cyclopropa(b)naphthalene, bicyclo(4.1.0)hepta-2,4,7-triene, and benzannelated derivatives have been calculated with a combined force field-SCF progrsm.The bicycloheptatrienes are stabilized relative to the isomeric arylcarbenes by benzannelation, and destabilized by loss of aromaticity and/or increased strain. 1-Naphthylcarbene, 2-naphthylcarbene, 9-phenanthrylcarbene and 9-anthrylcarbene were generated by gas-phase pyrolysis of the corresponding arene aldehyde tosylhydrazone sodium salts, diazomethanes, or 5-aryltetrazoles, and rearranged to cyclobutanaphthalene(21), cyclobutaphenanthrene(33), and cyclobutaanthracene(38), respectively. 10,11-Dihydrodibenzocyclohepten-5-ylidene (15), similarly generated from 5-diazo-10,11-dihydro-5H-dibenzocycloheptene (39), rearranged to 5a,9b-dihydro-5H-benzocyclobutindene(40), 5H-dibenzocycloheptene(41), and 8,9-dihydro-4H-cyclopentaphenanthrene(40). 40 rearranged thermally to 41.The mechanisms of the rearrangements are discussed.
- Wentrup, Curt,Mayor, Claude,Becker, Juergen,Lindner, Hans Joerg
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p. 1601 - 1612
(2007/10/02)
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