The literature has considered in detail the condensation reactions of aromatic aldehydes with 5H-furanones [1, 2]. Condensations of 5-substituted 3H-furanones have insufficient description jn the literature, and only relate to 5-aryl- and 5- methyl-3H-furan-2-ones [2, 3]; this is explained by the low availability of 5-alkyl-3H-furan-2-ones. On the basis of 4-oxoalkanoic acids, we obtained a series of 5-alkyl-3H-furan-2-ones, with the alkyl substituent from C3H 7 to C6H13, in ...