Theoretical and synthetic approach to novel spiroheterocycles derived from isatin derivatives and L-proline via 1,3-dipolar cycloaddition

A cyclic secondary -amino acid, viz. L-proline, reacts with isatin derivatives via decarboxylative azomethine ylide formation and subsequent cycloaddition with various dipolarophiles to give cycloadducts in moderate to good yield. Theoretical studies have been performed to study the stereochemistry of the products formed. (C) 2003 Wiley Periodicals, Inc.