Conformations of E-2-phenyl-3(2′-furyl)propenoic acid and its methyl ester in various solvents—an NMR study
作者:P. Forgó、K. Felföldi、I. Pálinkó
DOI:10.1016/j.molstruc.2004.11.052
日期:2005.6
The conformations of E-2-phenyl-3(2'-furyl)propenoic acid and its methylester were investigated by NMRspectroscopy. Applying various solvents (methanol, chloroform and dimethyl sulfoxide) the possible conformers in solutions were studied by two-dimensional NOESY measurements. Irrespective to the solvents and whether the investigated moiety was the ester or the acid dimer, no conformational preferences
By using iridium catalyst based on chiral spiro phosphine-oxazoline ligands, the hydrogenation of alpha-arylcinnamic acids was accomplished under ambient pressure and low catalyst loading (as low as 0.01 mol %), providing useful 2,3-diarylpropionic acids in high yields with excellent enantioselectivities (up to 99% ee). A catalytic enantioselective synthesis of (S)-equol with the present hydrogenation reaction as a key step was accomplished starting from commercially available starting materials in six steps with 48.4% overall yield. (C) 2012 Elsevier Ltd. All rights reserved.
Maccarone, Emanuele; Mamo, Antonino; Perrini, Giancarlo, Journal of Heterocyclic Chemistry, 1981, vol. 18, p. 395 - 398