133577-92-1Relevant academic research and scientific papers
Process for producing optically active gamma-butyrolactone
-
, (2008/06/13)
This invention provides a novel process for producing optically active 3-hydroxy-γ-butyrolactone in a short step, which is superior economically and in efficiency and industrially suitable by using a starting material which is inexpensive and easily available and reagents easy to handle. This invention relates to a process for producing optically active 3-hydroxy-γ-butyrolactone represented by formula I: wherein the symbol * means an asymmetric carbon atom, which comprises hydrogenating an optically active 4-substituted oxy-3-hydroxybutyrate represented by formula II: wherein R1 represents a C1-4 lower alkyl group, R2 represents a protective group for a hydroxyl group deprotected by hydrogenation with a heterogeneous hydrogenation catalyst, and the symbol * has the same meaning as defined above, in the presence of a heterogeneous hydrogenation catalyst and an acidic substance followed by deprotection and simultaneous ring closure thereof.
Method for producing 1-menthol
-
, (2008/06/13)
Provided is a method for the production of 1-menthol, which comprises hydrogenation of piperitenone with a transition metal complex of a specified optically active phosphine to produce pulegone, hydrogenation of the obtained pulegone with a ruthenium-phosphine-amine complex in the presence of base to obtain pulegol, and further hydrogenation of the pulegol with a transition metal catalyst.
Process for preparing oprtically active trimethyllactic acid and its ester
-
, (2008/06/13)
The invention relates to a novel process for preparing optically active trimethyllactic acid and/or its esters by catalytic hydrogenation of trimethylpyruvic acid and/or its esters in the presence of noble metal complex catalysts containing phosphorus ligands.
Chiral phosphorus compounds
-
, (2008/06/13)
Novel chiral phosphorus compounds of the formula STR1 wherein R signifies lower alkyl, R1 signifies phenyl and R2 and R3 signify hydrogen or lower alkoxy, which are suitable in the form of complexes with a metal of Group VIII as catalysts for asymmetric hydrogenations and for enantioselective hydrogen displacements in prochiral allylic systems.
Chiral phosphines
-
, (2008/06/13)
Novel, racemic and optically active phosphorus compounds of the formula STR1 wherein R signifies lower alkyl, lower alkoxy or protected hydroxy, R1 signifies lower alkoxy, phenoxy, benzyloxy, chlorine or bromine, R2 stands for lower alkyl or lower alkoxy and n represents the number 0, 1 or 2, are described. These compounds are valuable intermediates in the manufacture of not only known, but also novel diphosphine ligands.
Asymmetrical hydrogenation
-
, (2008/06/13)
There is disclosed a process for the asymmetrical hydrogenation of (E)-2-methyl-3-phenyl-2-propen-1-ol of formula STR1 wherein R1 is as defined herein, to give compounds of formula STR2 The catalyst is a neutral or cationic rhodium complex of a chiral atropisomeric phosphine.
Axially Dissymmetric Diphosphines in the Biphenyl Series: Synthesis of (6,6'-Dimethoxybiphenyl-2,2'-diyl)bis(diphenylphosphine) ('MeO-BIPHEP') and Analogues via an ortho-Lithiation/Iodination Ullmann-Reaction Approach
Schmid, Rudolf,Foricher, Joseph,Cereghetti, Marco,Schoenholzer, Peter
, p. 370 - 389 (2007/10/02)
The new axially dissymmetric diphosphines (R)- and (S)-(6,6'-dimethoxybiphenyl-2,2'-diyl)bis(diphenylphosphine) ((R)- and (S)-5a; 'MeO-BIPHEP') and the analogues (R)- and (S)-5b and 5c have been synthesized in enantiomerically pure form.These lignands hav
