RESUMO
A new and convenient stereocontrolled synthesis of the optically pure (S)-alpha-methyl,alpha-amino acids 6(a-d) that exploits the chiral synthon 1,4-N,N-[(S)-1-phenylethyl]-piperazine-2,5-dione (1) is described. The (S)-1-phenylethyl group, bonded to each of the N-atoms of the 2,5-diketopiperazine, acts as a chiral inductor in the first alkylation, while the steric hindrance appears to be the determining factor of stereocontrol in third and forth alkylation.
Assuntos
Aminoácidos/química , Aminoácidos/síntese química , Alanina/análogos & derivados , Alanina/síntese química , Alanina/química , Aminobutiratos/síntese química , Aminobutiratos/química , Cristalografia por Raios X , Dicetopiperazinas/síntese química , Dicetopiperazinas/química , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Conformação Molecular , Estereoisomerismo , Valina/síntese química , Valina/químicaRESUMO
The potential to inhibit alpha- and beta-glucosidases of a series of chiral piperazine-2,5-dione derivatives was investigated. Three of the seven compounds tested, viz., 1, 5b, and 5c, showed to be non competitive inhibitors of alpha-glucosidase, whereas they exhibited very low inhibitory activity towards beta-glucosidase. The most active compound, 5c (K(I) of alpha-glucosidase=5 microm), had a 100-fold alpha-glucosidase/beta-glucosidase inhibitor selectivity.