Synthesis of Novel Vicinal Coumarin- and Oxindole-Functionalized Dispiropyrrolidines and Dispiropyrrolizidines via [3+2]-Cycloaddition Reactions

Abstract

The synthesis of novel vicinal coumarin- and oxindole-functionalized dispiropyrrolidines and dispiropyrrolizidines containing three and four contiguous stereogenic centers, respectively, has been accomplished in excellent yields and with high regio- and stereoselectivity. The dispiro compounds are obtained via [3+2]-cycloaddition reactions between (E)-3-benzylidenechroman-2-one and the adduct generated from isatin and N-methylglycine or l-proline.