A Novel Entry into a New Class of (Chromanone-pyrrolidine/pyrrolizidine/pyrrolo[1,2-c]thiazole/pyrrolo[1,2-a]isoquinoline)indane-1,3-dione Ring Systems through [3+2] Cycloaddition
A highly regioselective synthesis of novel dispirohetero-cycles by the cycloaddition of azomethine ylide generated through a decarboxylative route from sarcosine/proline/thiazolidine-4-carboxylic acid/I.2.3,4-tetrahydroisoquinoline-3-carboxylic acid and ninhydrin with the dipolarophile 3-arylidene-4-chromanone is described.