

SYNTHESIS OF DISPIRO[1-BENZOTHIOPHENE-2,3'-PYRROLIDINE- 2',3''-INDOLINE]-2'',3-DIONES IN CYCLOADDITION REACTION

Abstract
The 1,3-dipolar cycloaddition of azomethine ylides derived from isatin and sarcosine to (Z)-2-(arylmethylidene)-1-benzothiophen-3(2H)-ones afforded novel dispiro[1-benzothiophene-2,3'-pyrrolidine-2',3''-indoline]-2'',3-diones in moderate yields. The structures of all the products were characterized by NMR, IR, HRMS together with X-ray crystallographic analysis. The reaction gives two diastereomeric products. This result is different from the cycloaddition of isatin, sarcosine, and other exocyclic olefins which generally afford only one
product.
product.
Keywords
azomethine ylide; 1-benzothiophen-3(2H)-one; isatin; sarcosine; 1,3-dipolar cycloaddition.
Latvian Institute of Organic Synthesis - Aizkraukles iela, 21, Riga, LV-1006, Latvia - hgs@osi.lv