Synthesis of novel 2'-aryl-4'-hydroxy-4',5,5',6-tetrahydro- 2'H,8H-spiro[indolizine-7,3'-thiophen]-8-one derivatives via sulfa-Michael/aldol cascade reactions

The sulfa-Michael/aldol cascade reaction of (E)-7-arylidene-6,7-dihydroindolizin-8(5H)-ones and 1,4-dithiane-2,5-diol afforded novel 2'-aryl-4'-hydroxy-4',5,5',6-tetrahydro-2'H,8H-spiro[indolizine-7,3'-thiophen]-8-ones in low to moderate yields. The structures of all products were characterized thoroughly by NMR, IR, HRMS, together with X-ray crystallographic analysis.