6-chloro-spirocyclohexenindol-2-ones: An unusual ring transformation to ethyl 2-(cyclohexa-1,4-dienyl)phenylcarbamates

Article abstract of DOI:10.1016/S0040-4020(99)00475-5

The Diels-Alder cycloaddition reaction of 3-chloromethylen-2-indolones 1 with a series of dienes 2 was studied in order to synthesize spirocyclohexenindolones 3 and 4. The reaction proceeded with good diastereoselectivity and regioselectivity. Chlorospiro