Protecting groups requirements

Deprotection of peptides. In a synthesis of bovine pancreatic ribonucleasc, the 33 protective groups required were removed by three treatments with l M TEMSA thioanisole at 0° for 60 minutes. The groups were Cbz, r-butyl, p-methoxybenzyl, and p-methoxybenzenesulfonyl. The final step involved air oxidation of the cysteine residues to disulfides mediated by glutathione.2... 

While the assembly of oligopeptides and oligonucleotides is routine and has become highly automated, the automated synthesis of oligosaccharides is still in its infancy despite some notable advances [82,83,84]. The situation becomes even more complex when the protecting group requirements for both the oligosaccharide assembly, and peptide assembly combine in the same molecule to stretch this aspect of chemical synthesis to its limits. Conse-... 

These accelerated growth procedures have been used by a number of groups to synthesize dendritic poly(amides),222-224 poly(esters),225 poly(ether urethanes),226 and chiral poly(ethers).227 The orthogonality of the focal and peripheral protecting groups required for double exponential growth also enables facile modification at either the periphery or focal point. Although this approach is one of the most rapid methods yet reported for the synthesis of well-... 

Fig. 3.2-3 Vinylsilanes as photocleavable protecting groups require E —> Z photoisomerization.

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