N-(Azido-PEG4)-N-Boc-PEG3-t-butyl ester

N-(Azido-PEG4)-N-Boc-PEG3-t-butyl ester enables Click Chemistry with alkyne such as DBCO , BCN or Propargyl reagent. Boc and the t-butyl protected carboxyl group can be deprotected under mild acidic conditions.