(indolinyl-5)-4 dihydro-2,5 furannone-2
1,2,3,6-Tetrahydrophthalic anhydride
acetyl-1 ethoxy carbonyl acetoxy acetyl-5 indoline
(acetyl-1 indolinyl-5)-4 dihydro-2,5 ethoxy carbonyl-3 furannone-2
(indolinyl-5)-4 dihydro-2,5 ethoxycarbonyl-3 furannone-2