The present invention is directed to novel fragrance compounds and their unexpected advantageous use in improving, enhancing or modifying a fragrance formulation through the addition of an olfactory acceptable amount of the compounds, wherein the compounds are represented by the following formula: an isomer or a mixture of isomers thereof, wherein one of R and R' represents hydrogen with the other representing a C 1 -C 6 linear, branched, or cyclic alkyl, alkenyl, alkynyl or aromatic group； and one of the dashed lines represents a carbon-carbon single bond with the other representing a carbon-carbon double bond.
