Synthesis and Biological Activities of 3‐Substituted Analogues of Tenuazonic Acid

A series of tenuazonic acid analogues in which the acetyl group was replaced with electron-withdrawing substituents have been synthesized with the aim of obtaining molecules with various bioactivities. Substituents such as cyano, sulfonyl, and amido were introduced at the 3-position of the pyrrolidine-2,4-dione nucleus of tenuazonic acid. 3-Cyano and sulfonyl pyrrolidine-2,4-dione compounds (2 and 6) were prepared via a Dieckmann cyclization as key step. 3-Amido pyrrolidine-2,4-dione compounds (9) were prepared by a microwave-assisted amidation reaction from corresponding 3-carboxylate derivative. The target compounds were evaluated; their herbicidal, fungicidal, and insecticidal activities, and the preliminary bioassay data showed that some 3-cyanopyrrolidine-2,4-diones 2 gave good insecticidal activity, whereas some 3-amido compounds 9 exhibited moderate to strong fungicidal activity against Pythium dissimile at 20mg/L.