Synthesis and Aroma Evaluation of A Octahydro Coumarin Derivative

A new racemic octahydrocoumarin derivative was synthesized from isophorone and its aroma characteristics were evaluated preliminarily. As a kind of fused-ring lactone compound, It could be used for the daily fragrances. Using palladium on carbon as catalyst, isophorone was reduced selectively to obtain dihydroisophorone; Methyl 3-(2,4,4-trimethyl-6-oxo-cyclohexyl)propanoate was obtained by Michael addition reaction of enamine of dihydroisophorone with methyl acrylate. It was then hydrolyzed under basic conditions, reduced with potassium borohydride to obtain δ-hydroxycarboxylic acid, and finally acid-catalyzed Intramolecular esterification of δ-hydroxy carboxylic acid to form a racemic octahydrocoumarin derivative, 5,7,7-trimethyl-octahydro-2H-benzopyran-2-one; The target compound were characterized by IR, ¹H NMR, ¹³C NMR and MS.