Peptides Boc-Ala-Asn/Gln-OH and Boc-Asn/Gln-Ala-OH were saponified with barium hydroxide to corresponding Asp/Glu-containing peptides. Under the conditions of saponification, Boc-Asn-Ala-OH additionally afforded Boc-Asp-OH, isopeptide Boc-Asp(Ala)-OH, and Boc-NHSuc>Ala-OH, with the third being the key intermediate in these transformations. Boc-Asp(OMe)-Ala-OMe underwent similar transformations under
肽 Boc-Ala-Asn/Gln-OH 和 Boc-Asn/Gln-Ala-OH 用
氢氧化钡皂化成相应的含 Asp/Glu 的肽。在皂化条件下,Boc-Asn-Ala-OH额外得到
Boc-Asp-OH、异肽Boc-Asp(Ala)-OH和Boc-NHSuc>Ala-OH,其中第三个是这些转化的关键中间体. Boc-Asp(OMe)-Ala-OMe 在用
重氮甲烷或
三乙胺处理下经历了类似的转化。
氢氧化钡皂化伴随着 N 端
氨基酸残基的高度差向异构化,而 Boc-Asp(OMe)-Ala-OMe
重氮甲烷处理的产物具有低度差向异构化。