(2-Phenyl-2-trimethylsilyl)ethyl (PTMSE) Esters - a Novel Carboxyl Protecting Group

A novel silicon-containing protecting group based on the known 2-(trimethylsilyl)ethyl system has been developed for the protection of the carboxylic group, e.g. in peptide chemistry. The new protecting group can be cleaved by treatment with tetra-n-butylammonium fluoride much more rapidly than the known 2-(trimethylsilyl)ethyl group, leading to less side reactions.