A novel process can be used for purifying methyl methacrylate (MMA) contaminated with low-boiling components by distillation, where the process involves producing MMA by oxidative esterification, and a crude product containing methyl propionate (MP), methyl isobutyrate (MIB), and methacrolein (MAL) as low-boiling components. The process is compatible with MMA produced from C.sub.2-based methacrolein containing the low-boiling components specified.

A formulation includes an active agent, a thickening/solidifying agent, and an antioxidant. The active agent is 9-cis-β-carotene (9CBC) or a derivative thereof of the following formula: ##STR00001##
where R.sub.2 is H or methyl; X is ##STR00002##
optionally substituted with one or more methyl groups; n is an integer of 0-16; and the asterisk represents the point of attachment to the cyclohexene ring.

A formulation includes an active agent, a thickening/solidifying agent, and an antioxidant. The active agent is 9-cis-β-carotene (9CBC) or a derivative thereof of the following formula: ##STR00001##
where R.sub.2 is H or methyl; X is ##STR00002##
optionally substituted with one or more methyl groups; n is an integer of 0-16; and the asterisk represents the point of attachment to the cyclohexene ring.

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 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 formulation includes an active agent, a thickening/solidifying agent, and an antioxidant. The active agent is 9-cis-β-carotene (9CBC) or a derivative thereof of the following formula:

##STR00001##

where R.sub.2 is H or methyl; X is

##STR00002##

optionally substituted with one or more methyl groups; n is an integer of 0-16; and the asterisk represents the point of attachment to the cyclohexene ring.

A formulation includes an active agent, a thickening/solidifying agent, and an antioxidant. The active agent is 9-cis-β-carotene (9CBC) or a derivative thereof of the following formula:

##STR00001##

where R.sub.2 is H or methyl; X is

##STR00002##

optionally substituted with one or more methyl groups; n is an integer of 0-16; and the asterisk represents the point of attachment to the cyclohexene ring.

The present invention relates to a novel process for oxidative esterification, generally for reaction of aldehydes with alcohols in the presence of oxygenous gases directly to give the corresponding ester in the presence of a heterogeneous catalyst, by means of which, for example, (meth)acrolein can be converted to methyl (meth)acrylate. The new catalyst has titanium dioxide as the main component of the support material. The catalysts are especially notable for high mechanical and chemical stability and for good catalytic performance even over very long periods. The process is an improvement in the catalyst service life, activity and selectivity over prior art catalysts which lose activity and/or selectivity relatively quickly in continuous operation in media having even a small water content.