Cyclization of 5-(2-chloroethoxy)-1,5-dihydro-2H-pyrrol-2-ones

The intramolecular cyclization of substituted 5-(2-chloroethoxy)-1,5-dihydro-2H-pyrrol-2-ones in the presence of lithium diisopropylamide hexamethylphosphoramide in tetrahydrofuran gave tetrahydropyrano[2,3-b]pyrrol-6(2H)-ones and 3,4-dihydro-2H-pyrrolo-[2,1-b][1,3]oxazin-6(8aH)-ones in moderate to good yields.