LAUSR

Abstract The N-sulfonyl spiroaziridine oxindole is a recently developed versetile precusor in synthesis of wide range of 3,3-disubstitued/spirooxindoles. It usually prepared in three steps from isatin and needs costly and limited available sulfinimides and hazardous peracid. A sequential and one-pot direct strategy for the synthesis of terminal N-sulfonyl spiroaziridine oxindole has been developed under ambient conditions with excellent yields (up to 95%) from easily accessible spiroepoxy oxindoles by regioselective ammination with aqueous ammonia and subsequent ring enclosure reaction of resulting 1,2-amino alcohol using easily available sulfonyl chloride and base. Other salient features of the protocol include inexpensive substrate requirement and ease of isolation of the desired product by performing single column chromatographic purification after two consecutive steps.