Cyclohexene derivatives and their use as odorants

A flavor or fragrancing compound according to formula (IVb)

• wherein
• R1 is hydrogen, methyl, or ethyl;
• R2 is hydrogen, C1-C6 alkyl, or C2-C6 alkenyl;
• R3 is hydrogen, methyl, or ethyl;
• or
• either R1 and R3 or R2 and R3 form together with the carbon atoms to which they are attached a 5- or 6-membered carbocyclic ring;
• R4, R5, R6, R7, R8 and R9 are independently selected from hydrogen, C1-C6 alkyl, or C2-C6 alkenyl;
• or
• R4+R9 together is a bivalent residue selected from —(CH2)n— wherein n is 1 or 2, —C(═C(CH3)2)—, and —C(═C(CH2CH3)2)—;
• and
• R10 is hydrogen, linear or branched C1-C5 alkyl, or linear or branched C2-C5 alkenyl;
• R is hydrogen and R′ is selected from hydroxyl or —OCOR13, wherein R13 is hydrogen, or C1-C3 alkyl;
• R and R′ are selected from methoxy and ethoxy;
• or
• R and R′ forming together with the carbon atom to which they are attached dioxolan, dioxane, carbonyl, or C═N—OH;
• provided that compounds of formula (IVb) wherein R1-R6, R8 and R9 are hydrogen and R7 is methyl are excluded.

A compound according to formula (IVa)

• wherein
• R1 is hydrogen, methyl, or ethyl;
• R2 is hydrogen, C1-C6 alkyl, or C2-C6 alkenyl;
• R3 is hydrogen, methyl, or ethyl;
• or
• either R1 and R3 or R2 and R3 form together with the carbon atoms to which they are attached a 5- or 6-membered carbocyclic ring;
• R4, R5, R6, R7, R8 and R9 are independently selected from hydrogen, C1-C6 alkyl, or C2-C6 alkenyl;
• or
• R4+R9 together is a bivalent residue selected from —(CH2)n— wherein n is 1 or 2, —C(═C(CH3)2)—, and —C(═C(CH2CH3)2)—;
• and
• R10 is hydrogen, linear or branched C1-C5 alkyl, or linear or branched C2-C5 alkenyl;
• R is hydrogen and R′ is selected from hydroxyl or —OCOR13, wherein R13 is hydrogen, or C1-C3 alkyl;
• R and R′ are selected from methoxy and ethoxy;
• or
• R and R′ forming together with the carbon atom to which they are attached dioxolan, dioxane, carbonyl, or C═N—OH;
• with the proviso that 4-acetoxymentha-1,8-diene and compound(s) of formula (IVa) wherein R1, R4 to R6, R8 and R9 are hydrogen, R7 is methyl and R+R′ forms together with the carbon atom to which they are attached a carbonyl group or R is hydrogen and R′ is hydroxyl are excluded.

A flavor or fragrancing compound of formula (IVa)

• wherein
• R1 is hydrogen, methyl, or ethyl;
• R2 is hydrogen, C1-C6 alkyl, or C2-C6 alkenyl;
• R3 is hydrogen, methyl, or ethyl;
• or
• either R1 and R3 or R2 and R3 form together with the carbon atoms to which they are attached a 5- or 6-membered carbocyclic ring;
• R4, R5, R6, R7, R8 and R9 are independently selected from hydrogen, C1-C6 alkyl, or C2-C6 alkenyl;
• or
• R4+R9 together is a bivalent residue selected from —(CH2)n— wherein n is 1 or 2, —C(═C(CH3)2)—, and —C(═C(CH2CH3)2)—;
• and
• R10 is hydrogen, linear or branched C1-C5 alkyl, or linear or branched C2-C5 alkenyl;
• R is hydrogen and R′ is selected from hydroxyl or —OCOR13, wherein R13 is hydrogen, or C1-C3 alkyl;
• R and R′ are selected from methoxy and ethoxy;
• or
• R and R′ forming together with the carbon atom to which they are attached dioxolan, carbonyl, dioxane, or C═N—OH;
• with the proviso that 4-acetoxymentha-1,8-diene and compound(s) of formula (IVa) wherein R1, R4 to R6, R8 and R9 are hydrogen, R7 is methyl and R+R′ forms together with the carbon atom to which they are attached a carbonyl group or R is hydrogen and R′ is hydroxyl are excluded.

A process comprising the step of reacting formylbutadiene

• wherein
• R1 is hydrogen, methyl, or ethyl;
• R2 is hydrogen, C1-C6 alkyl, or C2-C6 alkenyl;
• R3 is hydrogen, methyl, or ethyl;
• or
• either R1 and R3 or R2 and R3 form together with the carbon atoms to which they are attached a 5- or 6-membered carbocyclic ring;
• with a diene of formula C
• wherein
• R4, R5, R6, R7, R8 and R9 are independently selected from hydrogen, C1-C6 alkyl, or C2-C6 alkenyl;
• or
• R4+R9 together is a bivalent residue selected from —(CH2)n— wherein n is 1 or 2, —C(═C(CH3)2)—, and —C(═C(CH2CH3)2)—;
• resulting in the production of a compound formulae (Ia) or (Ib)
• characterized in that the formylbutadiene of formula B is prepared in situ from an α,β-unsaturated aldehyde of formula A
• in the presence of a methylenation catalyst and formalin.