摘要:
The invention relates to a method for producing 2,6-dioxabicyclo-(3.3.0)-octane-4,8-dione (I), comprising the oxidation of dianhydrohexitols (II-IV), or of corresponding hydroxy ketones, with an oxygen-containing gas in the presence of a catalyst composition, the reaction proceeding without the addition of halogen sources.
摘要:
The invention relates to a method for producing 2,6-dioxabicyclo-(3.3.0)-octane-4,8-dione (I), comprising the oxidation of dianhydrohexitols (II-IV), or of corresponding hydroxy ketones, with an oxygen-containing gas in the presence of a catalyst composition, the reaction proceeding without the addition of halogen sources.
摘要:
The invention relates to a method for producing aldehydes and ketones from easily accessible primary and secondary alcohols by oxidation with atmospheric oxygen or pure oxygen using a catalyst system which consists of a derivative of a free nitroxyl radical.
摘要:
The invention relates to a process for enzymatic deracemization of enantiomer mixtures of secondary alcohols by a combination of oxidation and reduction reactions by means of stereoselective alcohol dehydrogenases and the cofactors thereof, wherein one enantiomer of an optically active secondary alcohol is in a formal sense selectively oxidized to the corresponding ketone, which is subsequently reduced selectively to the optical antipode, while the reduced form of the cofactor is provided for the reduction reaction by means of an additional enzyme, characterized in that two alcohol dehydrogenases with opposite stereoselectivity and different cofactor selectivity and the two corresponding, different cofactors are used for the oxidation and reduction reactions, and the oxidized and reduced cofactors are interconverted in a parallel enzymatic reaction with the additional enzyme, the direction of the deracemization toward one of the two enantiomers being controllable by the selection of the two alcohol dehydrogenases or using the selectivity difference of the additional enzyme for the two cofactors.
摘要:
The invention relates to compositions based on 2,5-diisocyanato-1,4:3,6-dianhydro-2,5-dideoxy-D-manitol (I), 2,5-diisocyanato-1,4:3,6-dianhydro-2,5-dideoxy-D-glucitol (II), and/or 2,5-diisocyanato-1,4:3,6-dianhydro-2,5-dideoxy-L-iditol (III), alone or in any mixtures.
摘要:
The invention relates to the use of 2,5-diisocyanato-1,4:3,6-dianhydro-2,5-dideoxy-D-manitol (I), 2,5-diisocyanato-1,4:3,6-dianhydro-2,5-dideoxy-D-glucitol (II), and/or 2,5-diisocyanato-1,4:3,6-dianhydro-2,5-dideoxy-L-iditol (III).