title: Diastereoselective synthesis and estimation of the conformational flexibility of 6-oxoperhydropyridazine-3-carboxylic acid derivatives.
abstract: alpha,beta-Didehydroglutamates have been diastereoselectively transformed into 6-oxoperhydropyridazine-3-carboxylic acid derivatives (OPCAs), which constitute a new class of cyclic amino acid derivatives. Acylation at N-1 renders dipeptides which show considerable conformational rigidity. Semiempirical calculations suggest that OPCAs might force peptide turns with different amplitudes depending on the substitution pattern and relative stereochemistry of the substituents of the pyridazinone ring.
authors.affiliation: Departamento de Química Orgánica, Facultad de Química, Universidad Complutense, 28040-Madrid, Spain.
authors.forename: Carlos
authors.initials: C
authors.lastname: Alvarez-Ibarra
authors.forename: Aurelio G
authors.initials: AG
authors.lastname: Csákÿ
authors.forename: Cristina
authors.initials: C
authors.lastname: Gómez de la Oliva
mesh_terms: D000478:Alkylation; D000596:Amino Acids / Q000737:chemistry*; D002264:Carboxylic Acids / Q000138:chemical synthesis*; D002384:Catalysis; D002625:Chemistry, Organic / Q000379:methods; D003500:Cyclization; D004151:Dipeptides / Q000737:chemistry*; D004952:Esters / Q000737:chemistry; D005971:Glutamates / Q000737:chemistry; D013058:Mass Spectrometry; D008958:Models, Molecular; D015394:Molecular Structure; D011724:Pyridazines / Q000138:chemical synthesis*; D013237:Stereoisomerism
chemical_list: D000596:Amino Acids; D002264:Carboxylic Acids; D004151:Dipeptides; D004952:Esters; D005971:Glutamates; D011724:Pyridazines