Regioselective synthesis of novel spiropyrrolidines and spirothiapyrrolizidines through multicomponent 1,3-dipolar cycloaddition reaction of azomethine ylides.

A series of novel spiropyrrolidines and spirothiapyrrolizidines were synthesized via a three-component 1,3-dipolar cycloaddition reaction of isatin or acenaphthenequinone, sarcosine or thiaproline and 4-hydroxy-6-methyl-3-((E)-3-phenylacryloyl)-2H-pyran-2-ones in refluxing ethanol. Advantages of this method include the availability of starting materials, mild reaction conditions, high yields, and the complete regioselectivity observed.