RESUMEN
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.
Asunto(s)
Aminoácidos/química , Ácido Clorhídrico/química , Modelos Químicos , Estructura Molecular , Resonancia Magnética Nuclear Biomolecular , Rotación Óptica , Soluciones/química , Estereoisomerismo , Agua/química , Difracción de Rayos XRESUMEN
A selective, efficient, and fast access to (Z,E)-2,7-bis(4-cyanobenzylidene)cycloheptan-1-one (BCBCH), precursor of the synthetic antagonist of tissue-plasminogen activator (t-PA), is reported using a solid/solid aldolisation-crotonisation reaction on a supramolecular complex under microwave irradiation. The underlying mechanism is investigated from the crystal structure of the intermediate host-guest complex formed between permethylated gamma-cyclodextrin and (Z)-2-(4-cyanobenzylidene)cycloheptan-1-one.