Various processes for preparing aldaric acids, aldonic acids, uronic acids, and/or lactone(s) thereof are described. For example, processes for preparing a C.sub.5-C.sub.6 aldaric acid and/or lactone(s) thereof by the catalytic oxidation of a C.sub.5-C.sub.6 aldonic acid and/or lactone(s) thereof and/or a C.sub.5-C.sub.6 aldose are described.

Various processes for preparing aldaric acids, aldonic acids, uronic acids, and/or lactone(s) thereof are described. For example, processes for preparing a C.sub.5-C.sub.6 aldaric acid and/or lactone(s) thereof by the catalytic oxidation of a C.sub.5-C.sub.6 aldonic acid and/or lactone(s) thereof and/or a C.sub.5-C.sub.6 aldose are described.

Various processes for preparing aldaric acids, aldonic acids, uronic acids, and/or lactone(s) thereof are described. For example, processes for preparing a C.sub.5-C.sub.6 aldaric acid and/or lactone(s) thereof by the catalytic oxidation of a C.sub.5-C.sub.6 aldonic acid and/or lactone(s) thereof and/or a C.sub.5-C.sub.6 aldose are described.

There is provided a method for producing isobutylene, in which isobutylene is produced from isobutanol with a high selectivity while suppressing a decrease in the isobutanol conversion rate under pressure. In the method for producing isobutylene according to the present invention, a raw material gas containing isobutanol is brought into contact with a catalyst to produce isobutylene from isobutanol, the method including bringing the raw material gas containing isobutanol into contact with a catalyst at a linear velocity of 1.20 cm/s or more under a pressure of 120 kPa or more in terms of absolute pressure to produce isobutylene from isobutanol.

There is provided a method for producing isobutylene, in which isobutylene is produced from isobutanol with a high selectivity while suppressing a decrease in the isobutanol conversion rate under pressure. In the method for producing isobutylene according to the present invention, a raw material gas containing isobutanol is brought into contact with a catalyst to produce isobutylene from isobutanol, the method including bringing the raw material gas containing isobutanol into contact with a catalyst at a linear velocity of 1.20 cm/s or more under a pressure of 120 kPa or more in terms of absolute pressure to produce isobutylene from isobutanol.

A novel process can be used for preparing methacrylates, such as methacrylic acid and/or alkyl methacrylates, especially MMA. The process allows for prolonging of the catalyst service life and an increase in efficiency of the methacrylate preparation based on C2 or C4 raw materials, especially when proceeding from isobutylene or tort-butanol or ethylene as raw material. The process allows for performance for longer periods without disruption, with constant or even increased activities and selectivities. This gives rise to the possibility of performing such processes in a very simple, economically viable, and environmentally benign manner. In addition, it has been possible to minimize known safety risks that emanate from the methacrolein intermediate.

A novel process can be used for preparing methacrylates, such as methacrylic acid and/or alkyl methacrylates, especially MMA. The process allows for prolonging of the catalyst service life and an increase in efficiency of the methacrylate preparation based on C2 or C4 raw materials, especially when proceeding from isobutylene or tort-butanol or ethylene as raw material. The process allows for performance for longer periods without disruption, with constant or even increased activities and selectivities. This gives rise to the possibility of performing such processes in a very simple, economically viable, and environmentally benign manner. In addition, it has been possible to minimize known safety risks that emanate from the methacrolein intermediate.

Efficient methods of producing L-threonic acid from L-xylonic acid are disclosed.

Efficient methods of producing L-threonic acid from L-xylonic acid are disclosed.

Efficient methods of producing L-threonic acid from L-xylonic acid are disclosed.