173314-03-9Relevant academic research and scientific papers
Base-catalyzed ring openings of benzocyclobutenones and -ols
Bradley, J. C.,Durst, T.
, p. 1660 - 1665 (2007/10/02)
The base-catalyzed ring opening of a number of isomeric E- and Z-benzylidenebenzocyclobutenones and -ols has been studied in both protic and aprotic solvents.Cleavage of the C1-C2 bond results in the formation of stilbenes with mainly, and at times exclusively, retained stereochemistry.For the alcohols, these results point to an oxyanion-induced carbon-carbon bond cleavage leading to a vinyl anion that is protonated with retention of configuration in the protic solvents rather than to an electrocyclic ring opening to an alkoxy o-quinodimethane.Reaction of the Z isomer of benzylidenebenzocyclobutenol with methyllithium in THF at 20 deg C causes isomerization to the E isomer, cleavage of the C1-C2 bond, and recyclization of the resultant isomerized vinyl anion. - Key words: benzylidenebenzocyclobutenones, base-catalyzed ring opening; benzylidenebenzocyclobutenols, base-catalyzed ring opening.
