Cleavage and deprotection

Starting with (+)-26, L-noviose, the sugar moiety of antibiotic novobiocin, was obtained. Thus, (+)-26 was converted into 56, via 41, which on reaction with methyllithium followed by oxidative cleavage and deprotection gave L-noviose (Scheme 16).21... 

This is the most widely used class of SP linkers. Historically, the SPS of peptides (see Section 2.1) was developed using building blocks protected with acid-labile groups, thus allowing a convenient simultaneous cleavage and deprotection in the final step of the synthesis. Four commercially available acid-labile linkers are depicted in Fig. 1.7 in resin- and compound-bound forms. The preferred cleavage conditions for each linker are also provided. 

SCHEME 15.24 Convergent synthesis of A -linked glycopeptides by coupling of solid-supported peptide 191 to chitobiosyl amine 192 followed by cleavage and deprotection. 

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