SYNTHESES OF 2-ACETYL-3-HYDROXY-1-NORMAL-PROPYLPYRROLE FROM ISOMALTOL AND 1-NORMAL-ALKYL-3-HYDROXY-2-METHYL-4-PYRIDONES FROM MALTOL

2-Acetyl-3-hydroxyfuran (2) reacts with n-propylamine affording 2-acetyl-3-hydroxy-l-n-propylpyrrole (3) in 63% yield. The transformation of 2-methyl-3-hydroxy-4-pyrone (4) into 1-n-alkyl-3-hydroxy-2-methyl-4-pyridones is achieved by benzylation of the 3-hydroxyl group whereupon the product reacts with ammonia and the corresponding pyridone is obtained. The pyridone is alkylated with alkyl bromides and after hydrobromic acid in acetic acid cleavage of the 3-position ether function, 1-n-alkyl-3-hydroxy-2-methyl-4-pyridones are obtained in 48% overall yield.