Asymmetric synthesis. Practical production of D and L threonine. Dynamic kinetic resolution in rhodium and ruthenium catalyzed hydrogenation of 2-acylamino-3-oxobutyrates.
作者:J.P. Genet、C. Pinel、S. Mallart、S. Juge、S. Thorimbert、J.A. Laffitte
DOI:10.1016/s0957-4166(00)86108-x
日期:1991.1
Enantioselective syntheses of D and L threonine are described. Racemic methyl and ethyl 2-acylamino-3-oxobutyrate 1 were synthesized from the corresponding acetoacetates 6 and then hydrogenated stereoselectively via dynamic kinetic resolution with various chiral P * P Rh (I) 8 and Ru (II) 10 catalysts to give syn optically active alcohols which could be converted by hydrolysis and treatment with propylene oxide into threonine. The best results were obtained using (-) CHIRAPHOS Ru and (+) BINAP Ru as catalysts, in the hydrogenation step leading respectively to D threonine (ee: 99 %) and L threonine (ee: 94 %) in 26-34 % overall yields.