Synthesis of 2-Allyl-2,3-dihydro-1H-indol-3-ones Using in situ Claisen Rearrangement of 2,3-Dihydro-1H-indol-3-ones with Allyl Alcohols.

Treatment of 2,3-dihydro-1H-indol-3-ones with allyl alcohols in the presence of camphorsulfonic acid and magnesium sulfate at 130 °C gave, via condensation and a Claisen rearrangement, 2-allyl-2,3-dihydro-1H-indol-3-ones in good yields. The stereochemistry of the products was determined by NOE experiments.