The alkyl ester may be a C1-6 alkyl ester of an aliphatic hydroxy carboxylic acid having 2-7 carbon atoms, such as a 4-hydroxybutyric acid C1-4 alkyl ester.

An optically active tetrahydrofuranthiocarboxylic acid is converted to an alkyl ester and this ester is analyzed by chromatography with an optically active column.

The organic electrolyte contains 0.0008-1.2% by weight of an alkyl ester of an aliphatic hydroxy carboxylic acid.

The resulting protected alkyl ester alkyl ketoside is then alkylated at the C-4 position whereby the hydrogen of the C-4 hydroxyl group is replaced with an alkyl group to form an alkoxy group.

The present invention concerns the use as perfuming ingredient of a lower alkyl ester of 4,6,6-trimethyl-1,3-cyclohexadiene-1-carboxylate or 4,6,6-trimethyl-3-cyclohexene-1-carboxylate.