Substituted 1,3-dioxolan-4-ones and 1,3-dioxan-4-ones as fragrance ingredients

An aroma chemical composition comprising at least one compound of formula (I)

• or stereoisomers thereof,
• wherein
• R1 is linear or branched C1-C11-alkyl, linear or branched C2-C11-alkenyl or a 5-membered unsaturated heterocycle comprising oxygen atom as the heteroatom,
• R2 is H or linear or branched C1-C4-alkyl,
• or
• R1 and R2, together with the carbon atom they are bound to, combine to form an unsubstituted 5- or 6-membered cycloaliphatic ring,
• R3 is H, linear or branched C1-C4-alkyl, linear C1-C4-alkyl substituted with C1-C2-alkylthio;
• or phenyl,
• R4 is H or linear C1-C3 alkyl, and
• n is 0 or 1,
• wherein the compound of the formula (I) is not a compound wherein
• n is 0, R1 is isopropyl, R2 is H, R3 is H and R4 is H;
• n is 0, R1 is n-nonyl, R2 is H, R3 is methyl and R4 is H;
• n is 0, R1 is 4-methylpent-3-enyl, R2 is methyl, R3 is methyl and R4 is H;
• n is 0, R1 is n-propyl, R2 is H, R3 is methyl and R4 is H;
• n is 0, R1 is isopropyl, R2 is H, R3 is phenyl and R4 is H;
• n is 0, R1 is methyl, R2 is methyl, R3 is methyl and R4 is methyl;
• and
• n is 0, R1 is methyl, R2 is methyl, R3 is ethyl and R4 is ethyl.

A compound of formula (I)

• or stereoisomers thereof,
• wherein
• R1 is linear or branched C6-C11-alkyl, linear or branched C6-C11-alkenyl or a 5-membered unsaturated heterocycle comprising oxygen atom as the heteroatom,
• R2 is H or linear or branched C1-C4 alkyl,
• or
• R1 and R2, together with the carbon atom they are bound to, combine to form an unsubstituted 5-membered cycloaliphatic ring,
• R3 is H, linear or branched C1-C4-alkyl, linear C1-C4-alkyl substituted with C1-C2-alkylthio;
• or phenyl,
• R4 is H or linear C1-C3-alkyl,
• n is 0 or 1;
• where the compound of the formula (I) is not a compound wherein
• n is 0, R1 is n-nonyl, R2 is H, R3 is methyl and R4 is H;
• n is 0, R1 is 4-methylpent-3-enyl, R2 is methyl, R3 is methyl and R4 is H;
• n is 0, R1 is 1-ethylpentyl (heptan-3-yl), R2 is H, R3 is H and R4 is H;
• n is 0, R1 is 1-propyl-hex-1-enyl (non-4-en-4-yl), R2 is H, R3 is H and R4 is H;
• n is 0, R1 is n-hexyl, R2 is H, R3 is H and R4 is H;
• n is 0, R1 is n-hexyl, R2 is methyl, R3 is methyl and R4 is H;
• n is 0, R1 and R2 form together —(CH2)4—, R3 is methyl and R4 is methyl;
• n is 1, R1 is n-heptyl, R2 is H, R3 is methyl and R4 is H;
• n is 1, R1 is n-octyl, R2 is H, R3 is methyl and R4 is H;
• n is 1, R1 is n-hexyl, R2 is H, R3 is methyl and R4 is H;
• and
• n is 1, R1 and R2 form together —(CH2)4—, R3 is H and R4 is H.

A compound of formula (Ib)

• wherein
• R1 is linear C1-C6 alkyl,
• R2 is H, or linear C1-C3 alkyl,
• or
• R1 and R2, together with the carbon atom they are bound to, combine to form an unsubstituted 5-membered cycloaliphatic ring,
• R3 is H, or linear C1-C3 alkyl,
• R4 is H, or linear C1-C3 alkyl;
• where the compound of the formula (Ib) is not a compound wherein
• R1 is methyl, R2 is H, R3 is methyl and R4 is H;
• R1 is methyl, R2 is methyl, R3 is methyl and R4 is H;
• R1 is methyl, R2 is methyl, R3 is methyl and R4 is methyl;
• R1 is n-hexyl, R2 is H, R3 is methyl and R4 is H;
• and
• R1 and R2 form together —(CH2)4—, R3 is H and R4 is H.