S-acetyl-PEG4-t-butyl ester linker contains a sulfur acetyl group and a t-butyl ester. The sulfur acetyl group can be deprotected to form a thiol group. The t-butyl ester can be removed under acidic conditions. The hydrophilic PEG linker can increase the water solubility of the compound in aqueous media.
AxisPharm offers 5000+ PEG Linkers with high purity. Different kinds of PEG Reagents may be available by custom synthesis.