CH2COOH-PEG-CH2COOtBu

Alpha-(carboxymethyl)-omega-(tert-butyl-protected carboxymethyl) poly(ethylene glycol) (HOOCCH2-PEG-CH2COOtBu) is a heterobifunctional precision PEG derivative with a defined chain length. The two ends bear carboxymethyl and tert-butyl-ester-protected carboxymethyl groups, respectively. Discrete chain lengths with different degrees of polymerization are available. The carboxymethyl group can be activated for coupling with primary amines. Its single methylene group defines the local connection between the reactive carboxyl group and the polyether chain. 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.