High-pressure-promoted Diels-Alder approach to biaryls: application to the synthesis of the cannabinols family.
Diels-Alder reactions of a range of 1-(alkoxy/alkyl/halogen-substituted phenyl)buta-1,3-dienes with methyl propiolate carried out in a green ethanolic medium under 9 kbar pressure were investigated. The use of high pressure as activating method of the Diels-Alder reactions allows efficient and regioselective generation of a series of cyclohexadienyl-benzene cycloadducts that are oxidized to the corresponding biaryls. The alkoxy/alkyl/halogen-substituted biaryls produced are useful precursors for accessing substituted 6H-benzo[c]chromen-6-ones and the cannabinols family.
Dipartimento di Chimica, Università degli Studi di Perugia, via Elce di Sotto 8, 06123 Perugia, Italy. lucio@unipg.it
Lucio
L
Minuti
Andrea
A
Temperini
Eleonora
E
Ballerini
D002187:Cannabinol / Q000138:chemical synthesis* / Q000737:chemistry; D003500:Cyclization; D006846:Hydrocarbons, Halogenated / Q000138:chemical synthesis* / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure
D006846:Hydrocarbons, Halogenated; D002187:Cannabinol