One-Pot Construction of Functionalized Spiro-dihydronaphthoquinone-oxindoles via Hauser-Kraus Annulation of Sulfonylphthalide with 3-Alkylideneoxindoles.

The Hauser-Kraus annulation of sulfonylphthalide with 3-olefinic oxindole has been performed. This strategy, which involves a cascade Michael addition-Dieckmann cyclization-elimination sequence, offers rapid and convenient access to novel spiro-dihydronaphthoquinone-oxindoles in excellent yields with complete selectivity for the enolic form under mild reaction conditions.