t-Boc-Aminoxy-PEG4-Tos

t-Boc-Aminooxy-PEG4-Tos is a bifunctional crosslinker reagent with a t-Boc-aminooxy group and a tosyl group. The tosyl group is a very good leaving group for nucleophilic substitution. The protected aminooxy can be deprotected under mild acidic conditions. PEG5 spacer increases solubility in aqueous media.