Stereochemical π-Facial Selectivity of the Diels−Alder Reaction of Benz[a]aceanthrylene and 1,4-Diphenylbenz[a]aceanthrylene

Autor: Marilyn Wooten, Saadia Faiz, William H. Watson, Mitchell D. Miller, Ted Wiederhold, Joseph K. Agyin, Kurt L. Krause, Benjamin F. Plummer
Rok vydání: 1997
Předmět:
Zdroj: The Journal of Organic Chemistry. 62:9290-9294
ISSN: 1520-6904
0022-3263
DOI: 10.1021/jo971610t
Popis: The Diels−Alder (D−A) reaction of the twisted hydrocarbon 1,4-diphenylbenz[a]aceanthrylene (4) with dienophiles maleic anhydride, bromomaleic anhydride, and N-phenylmaleimide and with benzyne is reported. The stereochemistry of the products derived from the D−A reaction of 4 is compared with the products derived from reaction of planar benz[a]aceanthrylene (5) with maleic anhydride as a model. The endo regiochemical π-facial selectivity of 4 appears to be the result of the steric effect of a phenyl substituent as the transition state is reached. Compound 5 produces both endo and exo D−A adducts when treated with maleic anhydride. X-ray crystallographic analysis verifies the topology of the bromomaleic anhydride adduct of 4 and the maleic anhydride adduct of 5.
Databáze: OpenAIRE