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Synthese und Isolierung von Heptafulven und Sesquifulvalen
Author(s) -
Schenk Walter Karl,
Kyburz Rolf,
Neuenschwander Markus
Publication year - 1975
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19750580414
Subject(s) - chemistry , methyllithium , tropone , pyrolysis , cyclopentadiene , medicinal chemistry , organic chemistry , catalysis
The synthesis and isolation of heptafulvene ( 1 ) and sesquifulvalene ( 2 ) is reported: Acetoxy‐tropylium‐fluoroborate ( 10 ) may be prepared by addition of tropone to acetyl‐fluoroborate at low temperatures. The tropylium salt reacts easily with methyllithium and sodium cyclopentadienide to give the acetoxy‐methyl‐cycloheptatrienes 11 and the acetoxy‐cyclopentadienyl‐cycloheptatrienes 12 respectively. Gas‐phase pyrolysis of 11 and 12 affords in remarkably good yields heptafulvene ( 1 ) and sesquifulvalene ( 2 ), which are isolated in cristalline form at low temperatures. Spectroscopic as well as chemical evidence of the title compounds is presented.