ISSN:
0009-2940
Keywords:
Diastereoselective hydrogenation
;
Immobilized enantioselective rhodium(I)-diphosphane catalysts
;
Folic acid
;
(6S,S)-Folinic acid
;
5,6,7,8-Tetrahydrofolic acid
;
N-5-(menthyloxycarbonyl)-
;
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Asymmetric Catalysis, 67[1]. - Diastereoselective Hydrogenation of Folic Acid with Optically Active Rhodium(I)-Diphosphane ComplexesWith immobilized rhodium(I)-diphosphane catalysts supported on silica gel, the C = N bonds of the pyrazine ring of folic acid (1) are reduced with hydrogen in aqueous solution to give 5,6,7,8-tetrahydrofolic acid. A mixture of the two diastereomers 2a and 3a is obtained with (6S)- and (6R)-configuration, respectively, at the newly formed asymmetric center in the pterine system and (S)-configuration in the L-glutamic acid moiety. The unstable hydrogenation products are derivatized with (-)-menthyl chloroformate. An improved HPLC procedure for the analysis of the products has been developed. By using optically active chelate phosphanes as cocatalysts together with [Rh(cod)Cl]2, a diastereomeric excess of up to 24% of the natural isomer 2a with (6S,S)-configuration is attained in the heterogeneous hydrogenation of folic acid.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cber.19921250917
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