Bicyclo(3.3.1)nonanes and bicyclo(3.3.1)nonenes and their use as flavor or fragrance ingredient

A compound of formula (I)

• wherein
• R is isopropyl or iso-propenyl;
• R1 is hydrogen, methyl or ethyl;
• R2 and R3 are independently hydrogen, methyl, or ethyl;
• or
• R2 and R3 taken together is ethylidene;
• or
• R2 and R3 taken together is a divalent radical (CH2)2 which forms cyclopropane together with the carbon atom to which they are attached;
• R4 and R5 are independently hydrogen, hydroxy, C1 to C3 alkoxy, or C2 to C3 acyloxy;
• or
• R4 and R5 together with the carbon atom to which they are attached form a 1,3-dioxolane ring or a 1,3-dioxane ring;
• or
• R4 and R5 together with the carbon atom to which they are attached form a carbonyl group;
• the bond between C2 and C3 is a single bond, or the dotted line together with the bond between C2 and C3 represents a double bond;
• and
• the bond between C7 and C8 is a single bond, or the dotted line together with the bond between C7 and C8 represents a double bond.