One-Pot Synthesis of New Spiro[cyclopropane-1,3′-[3H]indol]-2′(1′H)-ones from 3-Phenacylideneoxindoles

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