80866-87-1Relevant academic research and scientific papers
A MODIFIED SYNTHESIS OF MOSHER'S ACID AND ITS USE IN A SENSITIVE STEREOISOMER ANALYSIS OF AMINO ACID DERIVATIVES
Hull, William E.,Seeholzer, Klaus,Baumeister, Marlies,Ugi, Ivar
, p. 547 - 552 (2007/10/02)
A convenient and sensitive method for stereoisomer analysis of amino acid derivatives is described.It is based on the (19)F NMR-analysis of mixtures containing epimers of N-.-methoxy-.-trifluoromethyl-phenylacetyl alanine (MTPA).An improved procedure for the synthesis of MTPA is given.
UTILISATION DE LA SYNTHESE ATROLACTIQUE POUR L'EVALUATION DE L'EFFICACITE D'INDUCTEURS DE SYNTHESE ASYMETRIQUE.
Hassine, B. Ben,Gorsane, M.,Geerts-Evrard, F.,Pecher, J.,Martin, R. H.,Castelet, D.
, p. 547 - 556 (2007/10/02)
Atrolactic syntheses have been carried out to evaluate the potentiality, in asymmetric syntheses, of chiral inducers.The (d,l)-hydroxyhelicenes 1, 2, the (d,l) sec. alcohols 3-12 and the (d,l)phenolic binaphtyl compound 15 have been used as inducers.The d. e. are collected in table I (6-100 percent).The atrolactic asymmetric synthesis has also been carried out using three optically active inducers, namely: (-)-quinine 13, (-)-10,11-dihydroquinine 14, and R(-)-2,2,2-trifluoro-1-(9-anthryl)ethanol 6.Diastereomeric and enantiomeric excesses equal or greater than 88 percent have been obtained in six cases out of sixteen: (d,l)-2-hydroxyheptahelicene 1 (d. e = 100 percent +/-2), (1-naphtyl)-(9-anthryl)methanol 3 (d. e = 90 percent); 2,2,2-trichloro-1-(9-anthryl)ethanol 7 (d. e = 100 percent +/-2), 2,2,2-tribromo-1-(9-anthryl)ethanol 8 (d. e = 100 percent +/-2), (-)-quinine 13 (e. e = 95.5 percent), and (-)-2,2,2-trifluoro-1-(9-anthryl)ethanol 6 (e. e = 88 percent).
Determination of Enantiomeric Composition of Partly Racemized Carotenols
Aareskjold, Kare,Liaaen-Jensen, Synnove
, p. 499 - 504 (2007/10/02)
Method for determining enantiomeric composition of various racemized carotenols by converting them into diastereomeric esters with subsequent analysis have been studied.Diastereomeric esters of (-)-camphanic acid with carotenols other than α-ketols could not be separated by HPLC.No separation was achieved for diastereomeric esters of methoxytrifluoromethylphenylacetic acid (MTPA). 1H NMR analysis in the presence of Eu(fod)3 of diastereomeric MTPA esters allowed quantitative determination of the enantiomeric composition of carotenols with 2-hydroxy-β- and 3-hydroxy-β-type end groups.
