摘要:
The present invention provides a process for reducing carbonyl compounds to hydroxy compounds, in particular stereoselectively reducing .alpha.-aminohaloketone derivatives, under mild conditions in an easy and simple manner, which comprises reacting a carbonyl compound of the general formula (1) with an organoaluminum compound of the general formula (4) to provide the corresponding alcohol compound of the general formula (5). ##STR1##
摘要:
A process for preparing optically active alcoholic compounds wherein a carbonyl compound is assymmetrically reduced in an economical and practical manner. The process comprises treating a prochiral carbonyl compound represented by the general formula (1) with an optically active organoaluminum compound represented by the general formula (2) to conduct asymmetric reduction, thereby preparing an optically active alcoholic compound represented by the general formula (3).
摘要:
Processes for efficiently producing .alpha.-halo ketones, .alpha.-halohydrins and epoxides on an industrial scale. The prosesses include one for producing an .alpha.-halo ketone of general formula (3) by decarboxylating a product of reaction between a carboxilic acid derivative of general formula (1) and a metal enolate prepared from an .alpha.-haloacetic acid of general formula (2) or an acceptable salt thereof, one for producing an by reducing the .alpha.-halo ketone (3), and one for producing an epoxide (13) by treating the .alpha.-halohydrin (11) with a base to effect ring closure. The above prosesses are particularly suitable for producing optically active .alpha.-halo ketones, .alpha.-halohydrins and epoxides from the corresponding .alpha.-amino acid derivatives. ##STR1##
摘要:
A process for producing optically active 1-halo-3-amino-4-phenyl-2-butanol derivatives from optically active 1-halo-3-amino-4-phenyl-2-butanone derivatives stereoselectively in a high yield by bringing the butanone derivatives into contact with microorganisms.
摘要:
An object of the present invention is to provide a process for producing a .beta.-amino-.alpha.-hydroxy acid derivative via efficient and industrially utilizable steps.The present invention provides a process for producing a .beta.-amino-.alpha.-hydroxy acid derivative represented by the general formula (2) given below which comprises hydrolyzing an .alpha.-amino-.alpha.', .alpha.'-dihaloketone derivative of the general formula (1) given below in the presence of a base, followed by protecting the amino group or without protecting the same. ##STR1##
摘要:
The present invention provides a process for producing 1,2-epoxy-3-amino-4-phenylbutane derivatives which comprises treating a 1-halo-2-hydroxy-3-amino-4-phenylbutane derivative with a base in an aprotic polar organic solvent or a mixed solvent composed of an aprotic polar organic solvent and water and then causing the resulting epoxide to crystallize out from a mixed solvent composed of an aprotic polar organic solvent and water.
摘要:
An object of the present invention is to provide a process for producing a .beta.-amino-.alpha.-hydroxy acid derivative via efficient and industrially utilizable steps.The present invention provides a process for producing a .beta.-amino-.alpha.-hydroxy acid derivative represented by the general formula (2) given below which comprises hydrolyzing an .alpha.-amino-.alpha.', .alpha.-dihaloketone derivative of the general formula (1) given below in the presence of a base, followed by protecting the amino group or without protecting the same. ##STR1##
摘要:
A process for efficiently producing (S,S)-2-alkoxycyclohexanols in a single step by using (.+-.)-trans-2-alkoxycyclohexanols which are inexpensive and can be easily obtained. The process comprises treating a (.+-.)-trans-2-alkoxycyclohexanol with a hydrolase originating in a microorganism and being capable of esterifying stereospecifically the R-isomer in the presence of an acyl donor under such conditions that no hydrolysis occurs substantially to thereby give (S,S)-2-alkoxycyclohexanols and (R,R)-2-alkoxycyclohexanol carboxylate and then taking up the (S,S)-2-alkoxycyclohexanols.
摘要:
A process belt for papermaking with a long operational life comprises an integrated structure of a reinforcing fibrous base material 6 and a polyurethane layer, the reinforcing fibrous base material being embedded in the polyurethane, wherein an inorganic filler selected from calcined kaolin clay, fused silica and zeolite is homogeneously dispersed in the polyurethane.
摘要:
A hydroxygallium phthalocyanine pigment is characterized by having a maximum peak wavelength within a range of from 810 nm to 839 nm in optical absorption spectrum in a wavelength range of from 600 nm to 900 nm.