83023-81-8Relevant academic research and scientific papers
Enantioselective, chromatography-free synthesis of β3-Amino acids with natural and unnatural side chains
Gerfaud, Thibaud,Chiang, Ying-Ling,Kreituss, Imants,Russak, Justin A.,Bode, Jeffrey W.
scheme or table, p. 687 - 696 (2012/07/13)
β3-Amino acids are key components of some pharmaceuticals, excellent surrogates for metabolically labile α-amino acids, and building blocks for chiral heterocycles. Unfortunately they are not easily accessible in enantiomerically pure form, especially when possessing unnatural side chains. A flexible, chromatography-free process for the synthesis of enantiopure β3-amino acids possessing natural and unnatural side chains is described. The procedure uses inexpensive starting materials and reagents and offers a good alternative to the hazardous and expensive Arndt-Eistert homologation of enantiopure α-amino acids. Its utility has been demonstrated with the preparative scale synthesis of two valuable β3-amino acids possessing unnatural side chains.
ANGIOTENSIN CONVERTING ENZYME INHIBITORS
-
, (2008/06/13)
Angiotensin converting enzyme inhibitors have the formula Z(CH. sub.2). sub.n CHR 1 COOCHR 2 COOHin which Z is--SR. sub. 3,--COCHR 4 NHCOR 5, STR1 or--NHCHR 7 COOH, R. sub.4, R. sub.5, R 6, and R 7, which may be the same or different, are each phenyl or alkylphenyl C 7-12,R 4 is hydrogen, alkyl C 1-6, NHR 8 or (CH 2) p R 9, R 2 is (CH 2) m XR 10, alkyl C 1-6 optionally substituted by a saturated 5-or 6-membered carbocyclic or heterocyclic ring, alkylhalo C 1-6, alkylcyano C 1-6, or alkyl phenyl C 7-12, the phenyl being optionally substituted by NO 2 or NH 2,X is O, S(O) q, C=O or NR 11, andR 10 is alkyl C 1-6, alkylhalo C 1-6, alkoxy C 1-6, alkoxy C 1-6 substituted by halogen, alkanoyl C 1-6, S(O) r R. sub.12, NR 13 R 14, phenyl, alkylphenyl C 7-12, naphthalenyl or a 5-membered unsaturated heterocyclic ring, n is an integer from 0 to 6,m and p, which may be the same or different, are each an integer from 1 to 6,R 9 is hydrogen, SR 15 or phenyl optionally substituted by OR 16,R 3 and R 15, which may be the same or different, are each hydrogen or alkanoyl C 1-6,R. sub.8 is hydrogen or COOR 17,q and r, which may be the same or different, are each 0, 1, or 2,R 11, R. sub.13, R. sub.14, R 16, and R 17, which may be the same or different, are each hydrogen or alkyl C 1-6, and R 12 is hydrogen, alkyl C 1-6 or phenyl.The compounds, and salts thereof, are useful as vasodilators.
Synthesis and Diels-Alder reactions of 2-alkyl-5-methylene-1,3-dioxolan-4-ones and 2-alkyl-3-acyl-5-methylene-1,3-oxazolidin-4-ones: Highly exo and diastereoface selective chiral ketene equivalents
Roush,Essenfeld,Warmus,Brown
, p. 7305 - 7308 (2007/10/02)
Chiral dienophiles 1-3 undergo highly exo and diastereoface selective Diels-Alder reactions. The Diels-Alder reactions of 3 are also highly exo selective under Lewis acid catalyzed conditions.
A Formylcarbonium Ion Synthon. Synthesis of 3-Thio-Substituted 2-Amino Acids and Thio-Substituted Enamines from 2-Acyloxyacrylonitriles
Oku, Akira,Hori-ie, Naofumi,Harada, Toshiro
, p. 609 - 612 (2007/10/02)
The utilization of 2-acyloxy-3-phenylthiopropionitriles (2) which were prepared by the Michael addition of thiophenol to 2-acyloxyacrylonitriles (CH2=C(CN)OCOR), as a formylcarbonium ion synthon, was demonstrated by the transformation of 2 into S-phenylcysteine and 2-phenylthio enamines.
Laboratory-Scale Enzymatic/Chemical Syntheses of D- and L-β-Chlorolactic Acid and D- and L-Potassium Glycidate
Hirschbein, Bernard L.,Whitesides, George M.
, p. 4458 - 4460 (2007/10/02)
This paper describes preparations of D- (and L-) chlorolactic acids having enantiomeric excesses greater than 97percent by D- (and L-) lactate dehydrogenase catalyzed reduction of chloropyruvic acid with NADH.In syntheses carried out on 0.1-0.5 mol scales
