Base-catalyzed ring openings of benzocyclobutenones and -ols

Autor:	T. Durst, J. C. Bradley
Rok vydání:	1995
Předmět:	chemistry.chemical_classification Base (chemistry) Chemistry Organic Chemistry Organic chemistry General Chemistry Ring (chemistry) Cleavage (embryo) Medicinal chemistry Catalysis
Zdroj:	Canadian Journal of Chemistry. 73:1660-1665
ISSN:	1480-3291 0008-4042
DOI:	10.1139/v95-205
Popis:	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 °C causes isomerization to the E isomer, cleavage of the C1—C2 bond, and recyclization of the resultant isomerized vinyl anion. Keywords: benzylidenebenzocyclobutenones, base-catalyzed ring opening; benzylidenebenzocyclobutenols, base-catalyzed ring opening.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::8ff297077415b94335e3686f588cb740 https://doi.org/10.1139/v95-205 Zobrazit plný text záznamu