Unusual amino acids VII. Asymmetric synthesis of 3- and 4- pyridylalanines
作者:Christian Döbler、H.-J. Kreuzfeld、M. Michalik、H.W. Krause
DOI:10.1016/0957-4166(95)00428-9
日期:1996.1
(Z)-2-N-Acylamino-3-pyridyl-acrylic acids and their esters were prepared by partially known procedures and hydrogenated in the presence of HBF4 to the corresponding optically active 2-N-acetyl-(or benzoyl-)-3-(3- or 4-pyridyl)-alanines or analogous methyl esters with enantiomeric excesses up to 90%. The rhodium complexes of PROPRAPHOS, 6a,b, or of O,N-bis(diphenylphosphino)-2-exo-hydroxy, 3-endo-methylamino-norbor-nane
通过部分已知的方法制备(Z)-2 - N-酰基氨基-3-吡啶基-丙烯酸及其酯,并在HBF 4存在下将其氢化成相应的旋光的2- N-乙酰基-(或苯甲酰基-)-。 3-(3-或4-吡啶基)-丙氨酸或对映体过量最高达90%的类似甲酯。PROPRAPHOS,所述的铑络合物6A,B,或ö,ñ -双(二苯基膦基)-2-外-羟基,3-内型-甲基氨基- norbor-娜内,6C,作为手性催化剂已经在HBF的存在下被使用4生成相应的吡啶鎓盐。重结晶的氨基酸衍生物的脱酰作用或游离氨基酸的进一步重结晶产生对映体纯的D-和L-吡啶基丙氨酸。