Phthalimide as a chromophoric tag in the circular dichroism determination of absolute configuration of α-aminoacid amides and dipeptides. A case of a dipeptide isostructurality
作者:P Skowronek、A Katrusiak、J Gawroński
DOI:10.1016/s0040-4020(02)01362-5
日期:2002.12
amides and methyl amides as well as N-phthaloyl dipeptide methyl esters give Cotton effects of opposite signs at around 220 and 240 nm. The signs of these Cotton effects are directly correlated with the absolute configuration of the N-phthaloyl substituted stereogenic center: for l-configuration the Cotton effect at 240 nm is positive and the Cotton effect at 220 is negative. The X-ray analysis shows that
既Ñ -phthaloyl氨基酸酰胺和甲基酰胺以及ñ -phthaloyl二肽甲酯给予在约220和240纳米的相反符号的棉花的效果。这些棉花效应的迹象与N-邻苯二甲酰基取代的立体异构中心的绝对构型直接相关:对于l-构型,在240 nm处的棉花效应为正,在220纳米下的棉花效应为负。X射线分析表明,由于分子的构象柔韧性和类似的甲氧羰基和异丙基空间要求,非对映异构的1,d和1,1 N-邻苯二甲酰基丙氨酰缬氨酸甲酯形成同构的正交疏水晶体。