Examples of such protecting groups are well known in the art, and include the fluorenemethyloxycarbonyl (Fmoc), benzyloxycarbonyl (Cbz), tbutoxycarbonyl (Boc), allyloxycarbonyl (aloc), 4-methoxytrityl (mtt), and 1-(4,4-dimethyl-2,6-dioxocyclohex-1-ylidene)ethyl (Dde) groups for amino protection.