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Titolo:
APPROACHES TO PSEUDOPEPTIDIC ERGOPEPTINES .3. CONSEQUENCES OF THE INCORPORATION OF AN ALPHA-AZAPHENYLALANINE RESIDUE INTO THE ERGOTAMINE OXA-CYCLOLIC SYSTEM
Autore:
CALCAGNI A; LUCENTE G; LUISI G; PINNEN F; ROSSI D; GAVUZZO E;
Indirizzi:
UNIV ROMA LA SAPIENZA,DIPARTIMENTO STUDI FARMACEUT I-00185 ROME ITALY UNIV ROMA LA SAPIENZA,DIPARTIMENTO STUDI FARMACEUT I-00185 ROME ITALY UNIV G DANNUNZIO,IST SCI FARMACO I-66100 CHIETI ITALY CNR,IST STRUTTURIST CHIM G GIACOMELLO I-00016 MONTEROTONDO ROMA ITALY
Titolo Testata:
Journal of the Chemical Society. Perkin transactions. I
fascicolo: 15, , anno: 1997,
pagine: 2223 - 2227
SICI:
0300-922X(1997):15<2223:ATPE.C>2.0.ZU;2-T
Fonte:
ISI
Lingua:
ENG
Soggetto:
MOLECULAR-STRUCTURE; CRYSTAL;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
22
Recensione:
Indirizzi per estratti:
Citazione:
A. Calcagni et al., "APPROACHES TO PSEUDOPEPTIDIC ERGOPEPTINES .3. CONSEQUENCES OF THE INCORPORATION OF AN ALPHA-AZAPHENYLALANINE RESIDUE INTO THE ERGOTAMINE OXA-CYCLOLIC SYSTEM", Journal of the Chemical Society. Perkin transactions. I, (15), 1997, pp. 2223-2227

Abstract

In the context of a research program aimed at synthesizing pseudopeptidic ergopeptines, the incorporation of an alpha-azaPhe residue into the peptidic moiety of ergotamine has been studied. Acylation of cyclo(-azaPhe-Pro-) 6 with (+)-(S)-2-benzyloxy-2-methylmalonyl monoethyl ester monochloride 5 gives the (E)-isoimide 7 as the predominant reactionproduct; contrary to expectation the conversion of 7 into the desiredimide isomer 8 proceeds with difficulty and is accompanied by decomposition, Hydrogenolysis of 8 leads stereospecifically to the pseudopeptidic oxa-cyclol ethyl ester 9, Subsequent rearrangement of the corresponding oxa-cyclol acyl-azide 11 in the presence of benzyl alcohol fails to give the pseudopeptidic ergotamine oxa-cyclol, The new stable pseudopeptidic aza-cyclol 12 containing the residue of the didehydroalanine has been isolated together with a comparable amount of the imino aza-cyclol derivative 13, The mechanism of the formation of the new products 12 and 13 and the unexpected stability of the (E)-isoimide 7 are discussed.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 22/09/20 alle ore 16:16:46