ChemInform Abstract: STUDIES RELATED TO THROMBOXANE A2: A FORMAL SYNTHESIS OF OPTICALLY ACTIVE 9α,11α-THIATHROMBOXANE A2 METHYL ESTER FROM LEVOGLUCOSAN

1984 ◽  
Vol 15 (40) ◽  
Author(s):  
V. N. KALE ◽  
D. L. J. CLIVE
Keyword(s):  
Methyl Ester ◽  
Thromboxane A2 ◽  
Optically Active ◽  
Formal Synthesis

ChemInform Abstract: A Formal Synthesis of Optically Active Clavicipitic Acids, Unusual Azepinoindole-Type Ergot Alkaloids.

ChemInform ◽  
2010 ◽  
Vol 31 (1) ◽  
pp. no-no
Author(s):  
Hirofumi Shinohara ◽  
Tsutomu Fukuda ◽  
Masatomo Iwao
Keyword(s):  
Ergot Alkaloids ◽  
Optically Active ◽  
Formal Synthesis

Rhodium-Catalyzed Asymmetric Addition of Arylboronic Acids to Glyoxylates: Access to Optically Active Substituted Mandelic Acid Esters

Synlett ◽  
2019 ◽  
Vol 30 (14) ◽  
pp. 1693-1697
Author(s):  
Diao Chen ◽  
Jian-Guo Liu ◽  
Xu Zhang ◽  
Ming-Hua Xu
Keyword(s):  
Catalytic System ◽  
Mandelic Acid ◽  
Optically Active ◽  
Antiplatelet Drug ◽  
Reaction Conditions ◽  
Formal Synthesis ◽  
Arylboronic Acids ◽  
Synthetic Utility ◽  
Enantioselective Addition ◽  
Acid Esters

A rhodium-catalyzed enantioselective addition of glyoxylates to arylboronic acids promoted by a simple chiral sulfinamide-based olefin ligand under mild reaction conditions is described. The reaction provides access to a variety of optically active substituted mandelic acid esters in good yields with up to 83% ee. The catalytic system is also applicable to pyruvate addition. The synthetic utility of this method is highlighted by a formal synthesis of the antiplatelet drug clopidogrel.

Synthesis of Optically Active Thromboxane A2 and Leukotriene D4 Receptor Antagonists

2014 ◽  
Vol 87 (1) ◽  
pp. 127-140 ◽  
Author(s):  
Souichirou Kawazoe ◽  
Yoshinori Okamoto ◽  
Masaki Yokota ◽  
Hirokazu Kubota ◽  
Ryo Naito ◽  
...  
Keyword(s):  
Thromboxane A2 ◽  
Optically Active ◽  
Receptor Antagonists ◽  
Leukotriene D4 ◽  
D4 Receptor

scholarly journals Comparative studies of the specificities of α-chymotrypsin and subtilisin BPN′. Studies with flexible and ‘locked’ substrates

1972 ◽  
Vol 126 (3) ◽  
pp. 659-665 ◽  
Author(s):  
T. N. Pattabiraman ◽  
W. B. Lawson
Keyword(s):  
Methyl Ester ◽  
Carbon Atom ◽  
Binding Site ◽  
Comparative Studies ◽  
Detrimental Effect ◽  
Optically Active ◽  
The Other ◽  
Optical Isomers ◽  
Polar Groups ◽  
Hydrolysis Of

Subtilisin BPN′ hydrolysed N-acetyl-l-3-(2-naphthyl)-alanine methyl ester, N-acetyl-l-leucine methyl ester and N-acetyl-l-valine methyl ester, faster than α-chymotrypsin. Of eight ‘locked’ substrates tested, only methyl 5,6-benzindan-2-carboxylate was hydrolysed faster by subtilisin, whereas the other esters were better substrates for chymotrypsin. Compared with the values for chymotrypsin, the stereospecific ratios during the hydrolysis of the optically active locked substrates by subtilisin were decreased by one and two orders of magnitude for bi- and tri-cyclic substrates respectively. The polar groups adjacent to the α-carbon atom of locked substrates did not contribute significantly to the reactivity of the more active optical isomers, but had a detrimental effect on the less active antipodes during hydrolysis by both the enzymes. These studies show that the binding site of subtilisin BPN′ is longer and broader than that of α-chymotrypsin.

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