An unexpected regio- and stereoselective [4+3] cycloaddition reaction of azomethine ylides with 5-benzylidenethiazolidine-2,4-diones has been successfully developed for the synthesis of the novel pharmacologically active 4′,5′-dihydro-3′Hspiro[indoline-3,2′-[1, 3] oxazepin]-2-one derivatives in basic condition. Easy purifcation, high yield, short experimental
time and operational simplicity are specifc advantages of this protocol. Furthermore, all the synthesized compounds have
been evaluated for antioxidant and antibacterial activities. According to the results, most of the synthesized compounds
exhibited DPPH radical scavenging activity and nine of them showed antibacterial properties. The reaction mechanism and
1
H NMR spectrum have been evaluated by B3LYP/6311G method.