The present invention provides a process for preparing 2-isopropenyl-5-methyl-4-hexenoic acid of the following formula (4), comprising steps of: subjecting a Grignard reagent of the following general formula (1), wherein R.sup.1 represents a linear, branched, or aromatic monovalent hydrocarbon group having 1 to 8 carbon atoms, and X represents a chlorine atom, a bromine atom, or an iodine atom, and 1,1,1,3,3,3-hexamethyldisilazane to a deprotonation reaction to form a 1,1,1,3,3,3-hexamethyldisilazane derivative; and subjecting 2-methyl-3-buten-2-yl 3-methyl-2-butenoate of the following formula (3) to a rearrangement reaction in the presence of the 1, 1, 1,3,3,3-hexamethyldisilazane derivative to form 2-isopropenyl-5-methyl-4-hexenoic acid (4).

##STR00001##

The present invention provides a process for preparing 2-isopropenyl-5-methyl-4-hexenoic acid of the following formula (4), comprising steps of: subjecting a Grignard reagent of the following general formula (1), wherein R.sup.1 represents a linear, branched, or aromatic monovalent hydrocarbon group having 1 to 8 carbon atoms, and X represents a chlorine atom, a bromine atom, or an iodine atom, and 1,1,1,3,3,3-hexamethyldisilazane to a deprotonation reaction to form a 1,1,1,3,3,3-hexamethyldisilazane derivative; and subjecting 2-methyl-3-buten-2-yl 3-methyl-2-butenoate of the following formula (3) to a rearrangement reaction in the presence of the 1, 1, 1,3,3,3-hexamethyldisilazane derivative to form 2-isopropenyl-5-methyl-4-hexenoic acid (4).

##STR00001##

The present invention relates to the use of an α,α-disubstituted carboxylic acid ester of the general formula (I) wherein the variables are as defined in the claims and the description, or of mixtures of two or more of these α,α-disubstituted carboxylic acid esters or of a stereoisomer thereof or of a mixture of two or more stereoisomers thereof as aroma chemicals; to the use thereof for modifying the scent character of a fragranced composition; to an aroma chemical composition containing an α,α-disubstituted carboxylic acid ester of the general formula (I) or a mixture of two or more of said α,α-disubstituted carboxylic acid esters or of a stereoisomer thereof or of a mixture of two or more stereoisomers thereof; and to a method of preparing a fragranced composition or for modifying the scent character of a fragranced composition. The invention further relates to specific mixtures of α,α-disubstituted carboxylic acid esters of the general formula (I).

##STR00001##

The present invention relates to the use of an α,α-disubstituted carboxylic acid ester of the general formula (I) wherein the variables are as defined in the claims and the description, or of mixtures of two or more of these α,α-disubstituted carboxylic acid esters or of a stereoisomer thereof or of a mixture of two or more stereoisomers thereof as aroma chemicals; to the use thereof for modifying the scent character of a fragranced composition; to an aroma chemical composition containing an α,α-disubstituted carboxylic acid ester of the general formula (I) or a mixture of two or more of said α,α-disubstituted carboxylic acid esters or of a stereoisomer thereof or of a mixture of two or more stereoisomers thereof; and to a method of preparing a fragranced composition or for modifying the scent character of a fragranced composition. The invention further relates to specific mixtures of α,α-disubstituted carboxylic acid esters of the general formula (I).

##STR00001##

The invention relates to compounds of formula (I)

##STR00001##

where
R.sup.1, R.sup.2, R.sup.3, R.sup.4 are each independently selected from —(C.sub.1-C.sub.12)-alkyl, —(C.sub.3-C.sub.12)-cycloalkyl, —(C.sub.3-C.sub.12)-heterocycloalkyl, —(C.sub.6-C.sub.20)-aryl, —(C.sub.3-C.sub.20)-heteroaryl;
at least one of the R.sup.1, R.sup.2, R.sup.3, R.sup.4 radicals is a —(C.sub.3-C.sub.20)-heteroaryl radical;
and
R.sup.1, R.sup.2, R.sup.3, R.sup.4, if they are —(C.sub.1-C.sub.12)-alkyl, —(C.sub.3-C.sub.12)-cycloalkyl, —(C.sub.3-C.sub.12)-heterocycloalkyl, —(C.sub.6-C.sub.20)-aryl or —(C.sub.3-C.sub.20)-heteroaryl,
may each independently be substituted by one or more substituents selected from —(C.sub.1-C.sub.12)-alkyl, —(C.sub.3-C.sub.12)-cycloalkyl, —(C.sub.3-C.sub.12)-heterocycloalkyl, —O—(C.sub.1-C.sub.12)-alkyl, —O—(C.sub.1-C.sub.12)-alkyl-(C.sub.6-C.sub.20)-aryl, —O—(C.sub.3-C.sub.12)-cycloalkyl, —S—(C.sub.1-C.sub.12)-alkyl, —S—(C.sub.3-C.sub.12)-cycloalkyl, —COO—(C.sub.1-C.sub.12)-alkyl, —COO—(C.sub.3-C.sub.12)-cycloalkyl, —CONH—(C.sub.1-C.sub.12)-alkyl, —CONH—(C.sub.3-C.sub.12)-cycloalkyl, —CO—(C.sub.1-C.sub.12)-alkyl, —CO—(C.sub.3-C.sub.12)-cycloalkyl, —N—[(C.sub.1-C.sub.12)-alkyl].sub.2, —(C.sub.6-C.sub.20)-aryl, —(C.sub.6-C.sub.20)-aryl-(C.sub.1-C.sub.12)-alkyl, —(C.sub.6-C.sub.20)-aryl-O—(C.sub.1-C.sub.12)-alkyl, —(C.sub.3-C.sub.20)-heteroaryl, —(C.sub.3-C.sub.20)-heteroaryl-(C.sub.1-C.sub.12)-alkyl, —(C.sub.3-C.sub.20)-heteroaryl-O—(C.sub.1-C.sub.12)-alkyl, —COOH, —OH, —SO.sub.3H, —NH.sub.2, halogen;
and to the use thereof as ligands in alkoxycarbonylation.

The invention relates to compounds of formula (I)

##STR00001##

where
R.sup.1, R.sup.2, R.sup.3, R.sup.4 are each independently selected from —(C.sub.1-C.sub.12)-alkyl, —(C.sub.3-C.sub.12)-cycloalkyl, —(C.sub.3-C.sub.12)-heterocycloalkyl, —(C.sub.6-C.sub.20)-aryl, —(C.sub.3-C.sub.20)-heteroaryl;
at least one of the R.sup.1, R.sup.2, R.sup.3, R.sup.4 radicals is a —(C.sub.3-C.sub.20)-heteroaryl radical;
and
R.sup.1, R.sup.2, R.sup.3, R.sup.4, if they are —(C.sub.1-C.sub.12)-alkyl, —(C.sub.3-C.sub.12)-cycloalkyl, —(C.sub.3-C.sub.12)-heterocycloalkyl, —(C.sub.6-C.sub.20)-aryl or —(C.sub.3-C.sub.20)-heteroaryl,
may each independently be substituted by one or more substituents selected from —(C.sub.1-C.sub.12)-alkyl, —(C.sub.3-C.sub.12)-cycloalkyl, —(C.sub.3-C.sub.12)-heterocycloalkyl, —O—(C.sub.1-C.sub.12)-alkyl, —O—(C.sub.1-C.sub.12)-alkyl-(C.sub.6-C.sub.20)-aryl, —O—(C.sub.3-C.sub.12)-cycloalkyl, —S—(C.sub.1-C.sub.12)-alkyl, —S—(C.sub.3-C.sub.12)-cycloalkyl, —COO—(C.sub.1-C.sub.12)-alkyl, —COO—(C.sub.3-C.sub.12)-cycloalkyl, —CONH—(C.sub.1-C.sub.12)-alkyl, —CONH—(C.sub.3-C.sub.12)-cycloalkyl, —CO—(C.sub.1-C.sub.12)-alkyl, —CO—(C.sub.3-C.sub.12)-cycloalkyl, —N—[(C.sub.1-C.sub.12)-alkyl].sub.2, —(C.sub.6-C.sub.20)-aryl, —(C.sub.6-C.sub.20)-aryl-(C.sub.1-C.sub.12)-alkyl, —(C.sub.6-C.sub.20)-aryl-O—(C.sub.1-C.sub.12)-alkyl, —(C.sub.3-C.sub.20)-heteroaryl, —(C.sub.3-C.sub.20)-heteroaryl-(C.sub.1-C.sub.12)-alkyl, —(C.sub.3-C.sub.20)-heteroaryl-O—(C.sub.1-C.sub.12)-alkyl, —COOH, —OH, —SO.sub.3H, —NH.sub.2, halogen;
and to the use thereof as ligands in alkoxycarbonylation.

Described herein are methods of preparing cutin-derived monomers, oligomers, or combinations thereof from cutin-containing plant matter. The methods can include heating the cutin-derived plant matter in a solvent at elevated temperature and pressure. In some preferred embodiments, the methods can be carried out without the use of additional acidic or basic species.

Described herein are methods of preparing cutin-derived monomers, oligomers, or combinations thereof from cutin-containing plant matter. The methods can include heating the cutin-derived plant matter in a solvent at elevated temperature and pressure. In some preferred embodiments, the methods can be carried out without the use of additional acidic or basic species.

Platinum complexes having ferrocene ligands for the catalysis of the alkoxycarbonylation of ethylenically unsaturated compounds.

Platinum complexes having ferrocene ligands for the catalysis of the alkoxycarbonylation of ethylenically unsaturated compounds.