Abstract:
A process for the preparation of a 1,2-diacetoxy ester comprises acetylation of an epoxide with an acetic anhydride in the presence of a quaternary phosphonium acetate catalyst or its complex with acetic acid.
Abstract:
Disclosed are catalysts comprising copper chromite, palladium and lanthanum having hydrogenation activity. The combination of copper chromite with palladium and lanthanum enhances catalyst activity more than the presence of either palladium alone or palladium in combination with alkali or alkaline earth metals. The catalysts are useful for the preparation of methanol from carbon monoxide and hydrogen and for the hydrogenation of carbonyl compounds such as, for example, aldehydes, ketones, and esters, to their corresponding alcohols. The catalysts may be used for the preparation of cyclohexanedimethanols from dialkyl cyclohexanedicarboxylates or of ethylene glycol from alkyl glycolates.
Abstract:
The present disclosure relates to the production of a 2,2,4,4-tetraalkylcyclobutane-1,3-diol. In one embodiment, the present invention relates to the production of a 2,2,4,4-tetraalkylcyclobutane-1,3-diol by hydrogenation of a 2,2,4,4-tetraalkylcyclobutane-1,3-dione in the presence of an iridium-promoted cobalt-based catalyst.
Abstract:
The present disclosure relates to the production of a 2,2,4,4-tetraalkylcyclobutane-1,3-diol. In one embodiment, the present invention relates to the production of a 2,2,4,4-tetraalkylcyclobutane-1,3-diol by hydrogenation of a 2,2,4,4-tetraalkylcyclobutane-1,3-dione in the presence of an iridium-promoted cobalt-based catalyst.
Abstract:
The present disclosure relates to the production of 2,2,4,4-tetraalkylcyclobutane-1,3-diol. In one embodiment, the present invention relates to the production of 2,2,4,4-tetraalkylcyclobutane-1,3-diol by hydrogenation of 2,2,4,4-tetraalkylcyclobutane-1,3-dione in the presence of a promoted copper-based catalyst.
Abstract:
Disclosed are catalysts comprising copper chromite, palladium and lanthanum having hydrogenation activity. The combination of copper chromite with palladium and lanthanum enhances catalyst activity more than the presence of either palladium alone or palladium in combination with alkali or alkaline earth metals. The catalysts are useful for the preparation of methanol from carbon monoxide and hydrogen and for the hydrogenation of carbonyl compounds such as, for example, aldehydes, ketones, and esters, to their corresponding alcohols. The catalysts may be used for the preparation of cyclohexanedimethanols from dialkyl cyclohexanedicarboxylates or of ethylene glycol from alkyl glycolates.
Abstract:
The present disclosure relates to the production of 2,2,4,4-tetraalkylcyclobutane-1,3-diol. In one embodiment, the present invention relates to the production of 2,2,4,4-tetraalkylcyclobutane-1,3-diol by hydrogenation of 2,2,4,4-tetraalkylcyclobutane-1,3-dione in the presence of a promoted copper-based catalyst.
Abstract:
The present invention comprises the use of sulfite additives to reduce discoloration of L-ascorbic acid produced from acid or aqueous solutions of 2-keto-L-gulonic acid. In one aspect, the present invention comprises a continuous process for producing L-ascorbic acid from an aqueous solution of 2-keto-L-gulonic acid. The use of sulfite additives reduces product stream color and improves product recovery by binding to high molecular weight reaction by-products. In a continuous process, the reaction stream is separated from residual sulfite and sulfite-bound by-products to produce a product stream enriched in aqueous ascorbic acid for recovery, and an enriched 2-keto-L-gulonic acid stream which is recycled to the reactor. The in situ use of sulfite additives during the reaction increases the overall yield of L-ascorbic acid, with no loss in selectivity of the synthesis.