HS-PEG-CH2COOtBu

Alpha-(sulfanyl)-omega-(tert-butyl-protected carboxymethyl) poly(ethylene glycol) (HS-PEG-CH2COOtBu) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear thiol and tert-butyl-ester-protected carboxymethyl groups, respectively. Discrete chain lengths with different degrees of polymerization are available. The thiol can add to maleimides or participate in disulfide formation, offering different molecular conjugation routes. The tert-butyl ester temporarily protects a carboxyl precursor. Appropriate acidic deprotection enables subsequent carboxyl activation and amide coupling. The two end groups can be coupled sequentially using compatible reactions and appropriate protection strategies, enabling surface immobilization, functional-molecule bridging, and directional spacer synthesis.

Customization available.