title: Is the optical rotation sign/absolute configuration relationship still a problem? Examples taken from unnatural quaternary aminoacids.
abstract: The optical rotation sign/absolute configuration relationships of several alpha-methyl-alpha-arylglycines have been reinvestigated by crystallographic methods, as they have been found to be inconsistent in recent literature. Assignments previously made by enzymatic resolution, by analogy with natural tertiary aminoacids were found to be erroneous in the case of these quaternary aminoacids.
authors.affiliation: UPRES-EA 3233, SMS, Institut de Recherche en Chimie Organique Fine, Université de Rouen, Mont Saint Aignan Cedex, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Ferron
authors.forename: Frédéric
authors.initials: F
authors.lastname: Guillen
authors.forename: Servane
authors.initials: S
authors.lastname: Coste
authors.forename: Gérard
authors.initials: G
authors.lastname: Coquerel
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Plaquevent
mesh_terms: D000596:Amino Acids / Q000737:chemistry*; D006851:Hydrochloric Acid / Q000737:chemistry; D008956:Models, Chemical; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D009904:Optical Rotation; D012996:Solutions / Q000737:chemistry; D013237:Stereoisomerism; D014867:Water / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D000596:Amino Acids; D012996:Solutions; D014867:Water; D006851:Hydrochloric Acid