- Epoxy amino acids produced from allylglycines intramolecularly cyclised to yield four stereoisomers of 4-hydroxyproline derivatives
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Derivatives of 2-amino-4-pentenoic acid (allylglycine) were efficiently resolved using Subtilisin or acylase. The side-chain unsaturated bond of the enantiomerically pure amino acid with tert-butoxycarbonyl (Boc) protection was smoothly epoxidized with m-chloroperbenzoic acid. When the Boc protection of the amino group was removed, the amino group intramolecularly attacked the side-chain epoxide, generating compounds with five-membered rings: the 4-hydroxyproline derivatives. Two diastereomeric products were formed through the cyclisation reaction, for example, (2S,4S)-4-hydroxyproline benzyl ester (cis-8) and (2S,4R)-4-hydroxyproline benzyl ester (trans-8) were formed from (2S)-amino acid with a side-chain epoxide. Compound (2S,4S)-4-hydroxyproline benzyl ester (cis-8) was transformed to a lactone (cis-hydroxyproline lactone, 10) with the removal of benzyl alcohol. The cis-conformation was essential for the intramolecular ester exchange reaction; in fact, no lactone formation was observed for the trans isomer (trans-8). The separation of cis-hydroxyproline lactone and the trans-isomeric hydroxyproline benzyl ester was facile and clear, in contrast to the difficult separation of cis- and trans-hydroxyproline derivatives. Thus, two diastereomers of hydroxyproline derivatives for l-hydroxyproline and also for d-hydroxyproline were obtained, i.e., four diastereomers of hydroxyproline derivatives.
- Krishnamurthy, Suvratha,Arai, Toru,Nakanishi, Kanae,Nishino, Norikazu
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p. 2482 - 2490
(2014/01/06)
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- Compounds and compositions for use in the prevention and treatment of obesity and related syndromes
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The invention relates to 4-hydroxyisoleucine, isomers, analogs, lactones, salts, and prodrugs thereof, to processes for their preparation, and to pharmaceutical compositions comprising the same. More particularly, the invention relates to the use of those compounds in the prevention and treatment of obesity and related syndromes.
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Page/Page column 60
(2010/11/24)
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- QUINAZOLINE DERIVATIVES
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The invention concerns quinazoline derivatives of Formula (I) wherein each of R1, R3, R20, X1, X2, Z, W, (a) and (q) have any of the meanings defined in the description; processes for their preparation, pharmaceutical compositions containing them and their use in the manufacture of a medicament for use as an antiproliferative agent in the prevention or treatment of turnours which are sensitive to inhibition of erbB receptor tyrosine kinases, particularly EGFR tyrosine kinase.
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Page/Page column 98
(2008/06/13)
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