91548-06-0Relevant academic research and scientific papers
Process for producing optically active gamma-butyrolactone
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, (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
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, (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.
Asymmetrical hydrogenation
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, (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.
Process for the manufacture of optically active compounds
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, (2008/06/13)
The manufacture of optically active bifunctional compounds of the general formula STR1 wherein R represents protected hydroxymethyl, protected formyl or alkoxycarbonyl and R1 represents a group of the formula STR2 or --CH2 --CH=NR2 in which R2 and R3 represent lower alkyl or cycloalkyl or R2 and R3 together with the nitrogen atom represent a heterocyclic ring, by isomerizing compounds of the general formula STR3 wherein R, R2 and R3 have the above significance and R3 can additionally signify hydrogen, is described. The compounds of formula I are potential intermediates in the manufacture of, inter alia, natural vitamin E and natural vitamin K1.
Phosphorus compounds
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, (2008/06/13)
Novel chiral phosphorus compounds of the general formula STR1 wherein R signifies substituted or unsubstituted phenyl, R1 and R2, which can be the same or different, signify hydrogen, lower alkyl, lower alkoxy, di-lower alkylamino or protected hydroxymethyl or R1 and R2 together signify the group STR2 in which m represents a number 3 to 5, R4 represents lower alkyl, substituted or unsubstituted phenyl or benzyl and R5 represents lower alkyl or both R5 's together represent lower alkylene, R3 signifies methyl, lower alkoxy, di-lower alkylamino or fluorine and n signifies the number 0, 1, 2 or 3, are described. The compounds of formula I are useful in the form of complexes with a metal of Group VIII as catalysts for asymmetric hydrogenations and enantioselective hydrogen displacements in prochiral allylic systems.
