On the acid-catalyzed rearrangement of β,γ-unsaturated ketones

✍ Scribed by Harold Hart; George M. Love

• Publisher: Elsevier Science
• Year: 1971
• Tongue: French
• Weight: 160 KB
• Volume: 12
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(01)96836-4

✦ Synopsis

The rearrangement of R,y-unsaturated ketones in acid has considerable potential for the synthesis of unusual bi-and tricyclic ring systems. In most examples described thus far, however, the double bond is present in the relatively strained cyclobutene ring.' We describe here a synthetically useful rearrangement of this type in which the double bond is in a sixmembered ring, but is located in a favorable geometry for interaction with the protonated ketone. Ketone ,j,' is readily accessible from hexamethyl-2,4-cyclohexadienone3 and benzyne. When i was refluxed with trifluoracetic acid for several hours, an equilibrium mixture of J,-t & H+ 1 (7%)