Ferf-butyl ethers protecting group

In peptide synthesis functional groups in the amino acid side chains are often protected with acid-labile protecting groups (Section 4.5.3). The tripeptide in Figure 4.35 contains, for example, a serine ferf-butyl ether and an L-lysine e-protected as an O-tert-butyl carbamate. In the standard strategy of synthesizing oligopeptides from the C- to the N-terminus (cf. Section 6.4.3) the C-terminus is either connected to the acid-labile... 

Protection of hydroxyl and carboxyl groups as ferf-butyl ethers and esters... 

FIGURE 3.22 Protection (A) of carboxyl groups of amino acids as ferf-butyl esters,58 (B) of carboxyl groups of /V-substituted amino acids as fert-butyl esters,61 and (C) of phenolic and sulfhydryl groups as ethers. The amino acid esters are isolated as the hydrochlorides. 

The protection of a hydroxyl group as a ferf-butyl trimethylsilyl ether is one of the most important and useful reaction in organic synthesis because of its stability towards basic and mild acidic conditions [144]. The importance of any protecting group depends on how easily it can be installed and removed. 

Enaminoketoesters were reacted with benzyl chloroformiate in the presence of sodium hydride to furnish the /V-protected enaminoketoesters. The reduction of the carbonyl group with NaBkLt in methanol was followed by transformation of the derived hydroxyl group into the corresponding ferf-butyl dimethylsilyl ether by... 

The 2-phenylprop-2-yl (1-methyl-1-phenylethyl) ester, although closely resembling the tert-butyl group, is more sensitive toward acids due to its phenyl group.It can also be considered as a substituted benzyl ester. 2-Phenylprop-2-yl esters of Fmoc-, Z-, or Boc-protected anoino acids are prepared via the 2-phenylprop-2-yl trichloroacetinoidates in the absence of any catalyst.These esters are cleaved with 2-4% TFA in CH2CI2, leaving N-Boc and ferf-butyl esters and ethers intact. 

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