Phenacyl esters as a new photocleavable linker in liquid-phase chemistry

PEG-supported 2-methylphenacyl ester as a new photocleavable linker is reported. The photocleavage based on an efficient intramolecular hydrogen abstraction was carried out with 280-366 nm UV irradiation in benzene or methanol to give the corresponding carboxylic acid in high yields and purities. The linker was suitable for aliphatic and aromatic carboxylic acids as well as protected amino acids.