叔丁氧羰基

利用叔丁氧羰基酸酐（（Boc）2O）对Tris上的氨基进行保护，对mPEG端羟基依次进行羧基化、酰氯化等活化处理，通过酰氯与羟基的官能团反应合成出目标分子。

The first step was to protect the amino group of Tris by using t-butyloxycarbonyl anhydride (( Boc ) 2O ), then mPEG was activated by changing hydroxide terminal into acid chloride and carboxylation of mPEG was fulfilled before .

目的：探讨非天然氨基酸N-叔丁氧羰基化反应的适宜溶剂系统。

Objective : To study the solvent systems suitable for N-tert-butoxycarbonylation of non-natural amino acids .

结论：水-四氢呋喃溶剂系统较适用于脂溶性大的非天然氨基酸N-叔丁氧羰基化，收率高，后处理简单。

Conclusion : Water-THF system is suitable for N-tert-butoxycarbonylation of lipophilic non-natural amino acids , with high yield and simple post-treatment .