87392-05-0Relevant articles and documents
Preparation process of optically pure 2-tetrahydrofuroic acid
-
Paragraph 0026; 0030; 0031, (2019/05/15)
The invention discloses a preparation process of optically pure 2-tetrahydrofuroic acid. The preparation process comprises the following steps: carrying out a splitting reaction on L-phenylalaninol with (RS)-2-tetrahydrofuroic acid in a first organic solvent to obtain a diastereoisomer salt, carrying out recrystallization to obtain an (S)-2-tetrahydrofuroic acid crude product, and carrying out post-treatment on the crude product to obtain high-optical purity (S)-2-tetrahydrofuroic acid with an enantiomeric excess (ee) value larger than 99%; and combining the mother liquor with the recrystallization mother liquor to obtain a mixed solution containing (R)-2-tetrahydrofuroic acid, then carrying out a reaction on the (R)-2-tetrahydrofuroic acid in the mixed solution with D-phenylalaninol for saltifying, recrystallizing the obtained salt to obtain an (R)-2-tetrahydrofuroic acid crude product, and carrying out post-treatment on the crude product to obtain high-optical purity (R)-2-tetrahydrofuroic acid with an ee value larger than 99%. According to the invention, the 2-tetrahydrofuroic acid is effectively split by using the two configurations of optically pure phenylalaninol, and the twooptical isomers of the 2-tetrahydrofuroic acid are separately obtained, and the ee values of the two optical isomers are both larger than 99%; secondly, the solvents, such as acetone, ethyl acetate and the like which are low in price and low in boiling point are used as solvents for the splitting reaction and recrystallization, the solvents are easy to recycle, and the recovery rate is high.
Highly diastereoselective hydrogenation of furan-2-carboxylic acid derivatives on heterogeneous catalysts
Sebek, Michael,Holz, Jens,B?rner, Armin,J?hnisch, Klaus
experimental part, p. 461 - 465 (2009/08/09)
The heterogeneously catalyzed diastereoselective hydrogenation of furan-2-carboxylic acid derivatives modified with chiral auxiliaries is described. Chiral auxiliaries, catalysts, solvents, and additives were optimized for the reaction. Finally, the hydro
Synthesis, Structure, and Pharmacological Evaluation of the Stereoisomers of Furnidipine
Alajarin, Ramon,Vaguero, Juan J.,Alvarez-Builla, Julio,Pastor, Manuel,Sunkel, Carlos,et al.
, p. 2830 - 2841 (2007/10/02)
The synthesis and pharmacological activities of the four stereoisomers of methyl tetrahydrofuran-2-ylmethyl 2,6-dimethyl-4-(2'-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylate (furnidipine) are reported.The four isomers were synthesized by a modified Hantzsch synthesis by reaction of (-)- or (+)-tetrahydrofuran-2-ylmethyl 3-aminocrotonate and methyl 2-acetoacetate or, alternatively, by reaction of (-)- or (+)-tetrahydrofuran-2-ylmethyl 2-acetoacetate and methyl 3-aminocrotonate.The 1:1 diasteromeric mixture thus obtained were separated by chromatography, using poly(D-phenylglycine) as the chiral stationary phase.The enantiomeric purity of the stereoisomers was determined by high-performance liquid chromatography-chiral stationary phase technique (HPLC-CSP).Attempts to obtain crystals of a single stereoisomer failed in different solvent, while methanol crystallization of the product obtained from (+/-)-tetrahydrofuran-2-ylmethyl 2-acetoacetate and methyl 3-aminocrotonate yielded good-quality crystals of the most insoluble racemate which proved to be a mixture of the (SS)/(RR) enantiomers by X-ray crystaloography.Conformational analysis of the stereoisomers, assuming rotation of the aryl substituent and ester groups, shows small energy differences (about 4 kcal*mol-1) between the most and the least favorable conformations.Binding studies were performed using isradipine as a reference ligand.The results showed stereospecificity of the furnidipine isomers in brain, ileum, and cardiac tissues, the (SS) and (SR)-isomers clearly being more potent than their (RR)- and (RS)-enantiomers.The (SS)- and (SR)-isomers were also more selective on cerebral tissue when compared with ileal and cardiac preparations.
