Investigations on the stereospecificity of peptide active phenyl ester formation and coupling
作者:J. Kovacs、L. Kisfaludy、M.Q. Ceprini、R.H. Johnson
DOI:10.1016/s0040-4020(01)82801-5
日期:1969.1
preparation of active esters by methods (b), (c), and (d), it was found that the more acidic the phenol component the greater was the optical purity of the ester formed. Method (d) generally afforded the highest optical purity. Under coupling conditions similar to those employed for the preparation of sequential polypeptides using pentachlorophenyl esters, no racemization was encounted as shown by the Anderson
研究了酚类活性酯在形成和随后偶联过程中的立体定向性。ZGlyPheOH,ZGlyGlyPheOH和BzLeuOH的不同酯可通过以下方法制备:(a)支持程序,(b)常规DCC方法,( c)反向DCC程序,或(d)使用由异脲衍生物“ A”和2 PCPOH组成的结晶“络合物”。通过方法(b),(c)和(d)制备活性酯时,发现酚组分的酸性越强,所形成的酯的旋光纯度就越高。方法(d)通常提供最高的光学纯度。在类似于使用五氯苯基酯制备连续多肽所采用的偶联条件下,未发生外消旋作用,如安德森外消旋试验所示。