3‐(2‐Pyrrolidinyl)‐2,4‐furandione analogs

Abstract The reaction of 4,4‐dimethyl‐3‐oxobutanoic (or pentanoic) acid esters with the lactim ether of 2‐pyrrolidone in the presence of 2‐hydroxypyridine produces condensation products 4 in 57–72% yield. Acidic hydrolysis of 4 affords the furandione system 5 in 75–81% yield.