A process for direct esterification of an alkyl aldehyde with an alkyl alcohol to produce an alkyl ester is disclosed. The process comprises reacting an alkyl aldehyde with an alkyl alcohol in the presence of an Au/TiOa catalyst, a base and an enal or oxygen to form an ester and an aldehyde. The process avoids liberation of water and avoids the step of oxidation of the alkyl aldehyde to an alkyl acid.

A process for direct esterification of an alkyl aldehyde with an alkyl alcohol to produce an alkyl ester is disclosed. The process comprises reacting an alkyl aldehyde with an alkyl alcohol in the presence of an Au/TiOa catalyst, a base and an enal or oxygen to form an ester and an aldehyde. The process avoids liberation of water and avoids the step of oxidation of the alkyl aldehyde to an alkyl acid.

A process for producing isomerized olefins, branched aldehydes, branched alcohols, branched surfactants and other branched derivatives through isomerization, hydroformylation, hydrogenation, surfactant forming reactions and other derivative forming reactions.

A process for producing isomerized olefins, branched aldehydes, branched alcohols, branched surfactants and other branched derivatives through isomerization, hydroformylation, hydrogenation, surfactant forming reactions and other derivative forming reactions.

[Problem] An ester compound having low viscosity, excellent fluidity even at low temperatures, and a high viscosity index; and a lubricating oil base oil containing said compound are provided. [Solution] The present invention provides an ester compound indicated by formula (I). Formula (I) (in formula (I), R.sub.1 is a hydrocarbon group having 1 to 35 carbon atoms and at least one hydrogen in the hydrocarbon group may be independently substituted with a group indicated by formula (II)). Formula (II) (in formula (II), R.sub.2 is a linear alkyl having 1 to 30 carbon atoms or a branched alkyl having 3 to 30 carbon atoms.)

[Problem] An ester compound having low viscosity, excellent fluidity even at low temperatures, and a high viscosity index; and a lubricating oil base oil containing said compound are provided. [Solution] The present invention provides an ester compound indicated by formula (I). Formula (I) (in formula (I), R.sub.1 is a hydrocarbon group having 1 to 35 carbon atoms and at least one hydrogen in the hydrocarbon group may be independently substituted with a group indicated by formula (II)). Formula (II) (in formula (II), R.sub.2 is a linear alkyl having 1 to 30 carbon atoms or a branched alkyl having 3 to 30 carbon atoms.)

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 provides a novel compound, (4Z,6E)-4,6-undecadienyl trimethylacetate (1). The present invention further provides a process for preparing (4Z,6E)-4,6-undecadienyl trimethylacetate (1), the process comprising subjecting a 4-halobutyl trimethylacetate compound (2) wherein X.sup.1 represents a halogen atom, to a phosphonium salt formation reaction with a phosphine compound of the following general formula (3) wherein Ar represents, independently of each other, an aryl group, to obtain a [4-(trimethylacetyloxy)butyl]triarylphosphonium halide compound (4) wherein Y represents a halogen atom, and Ar is as defined above, subjecting the [4-(trimethylacetyloxy)butyl]triarylphosphonium halide compound (4) to a deprotonation reaction in the presence of a base to obtain a reaction product mixture, and subjecting the reaction product mixture to a Wittig reaction with (2E)-2-heptenal (5) to obtain (4Z,6E)-4,6-undecadienyl trimethylacetate (1).

##STR00001##

The present invention provides a novel compound, (4Z,6E)-4,6-undecadienyl trimethylacetate (1). The present invention further provides a process for preparing (4Z,6E)-4,6-undecadienyl trimethylacetate (1), the process comprising subjecting a 4-halobutyl trimethylacetate compound (2) wherein X.sup.1 represents a halogen atom, to a phosphonium salt formation reaction with a phosphine compound of the following general formula (3) wherein Ar represents, independently of each other, an aryl group, to obtain a [4-(trimethylacetyloxy)butyl]triarylphosphonium halide compound (4) wherein Y represents a halogen atom, and Ar is as defined above, subjecting the [4-(trimethylacetyloxy)butyl]triarylphosphonium halide compound (4) to a deprotonation reaction in the presence of a base to obtain a reaction product mixture, and subjecting the reaction product mixture to a Wittig reaction with (2E)-2-heptenal (5) to obtain (4Z,6E)-4,6-undecadienyl trimethylacetate (1).

##STR00001##