Electrocyclic reactions. Part III. Some reactions of 2,4-dimethyl-1,5-diphenylpenta-1,4-dien-3-one (αα′-dimethyldibenzylideneacetone)

Autor:	Charles W. Shoppee, Burgess J. A. Cooke
Rok vydání:	1973
Předmět:	Part iii Cyclopentenone chemistry.chemical_compound Chemistry Organic chemistry Hydrochloric acid Conrotatory and disrotatory Cyclopentanone Ground state Medicinal chemistry
Zdroj:	J. Chem. Soc., Perkin Trans. 1. :1026-1030
ISSN:	1364-5463 0300-922X
DOI:	10.1039/p19730001026
Popis:	αα′-Dimethyldibenzylideneacetone (I) by treatment with hot hydrochloric acid givestrans-2,5-dimethyl-3,4-diphenylcyclopent-2-enone (Va). With hot hydriodic acid the minor product is the cyclopentenone (Va) and the major product is trans-2,5-dimethyl-trans-3,4-diphenylcyclopentanone (VIa). The cyclopentenone (Va) undergoes only partial reduction with hot hydriodic acid to the cyclopentanone (VIa). The results suggest a conrotatory thermal ground state electrocyclisation of a pentadienyl cation to a cyclopentenyl cation, followed by loss of a proton and ketonisation, or by reduction. The high yields of cyclic products, relative to those observed for trans,trans-dibenzylideneacetone, are notable.
Databáze:	OpenAIRE
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