One‐pot synthesis of new spiro[cyclopropane‐1,3′‐[3 H ]indol]‐2′(1′ H )‐ones from 3‐phenacylideneoxindoles

In a one‐pot procedure, the 3‐phenacylideneoxindoles 1a , 1b , 1c , 1d were reacted with hydrazine and then in situ with lead(IV) acetate and new diastereoisomers of spiro[cyclopropane‐1,3′‐[3 H ]indol]‐2′(1′ H )‐ones were prepared. Compounds 1a , 1b , 1c , 1d underwent a highly diastereoselective cyclopropanation leading to diastereoisomers 2a , 2b , 2c , 2d . These new compounds containing both 2‐oxindole and cyclopropane moieties may be valuable in medicinal chemistry. J. Heterocyclic Chem., (2010).