Towards a selective Boc deprotection on acid cleavable Wang resin

Deprotection of the Boc group of an amino acid attached to the Wang resin has been investigated. Several conditions, including bases, solvents and reaction time, were studied. Quantitative yield of Boc deprotection was achieved with less than 10% loss of resin loading with trimethylsilyltriflate. This reagent allows the replacement of tert-butyl to TMS group, leading to a new temporary urethane protection readily hydrolyzed.