Deprotection by Reduction Hydrogenolysis

FIGURE 3.3 Deprotection of functional groups by reduction. Hydrogenolysis of benzyl-based protectors.1 Attack by electrons liberates the protector as the benzyl anion because the latter is stabilized by resonance. This is a simplified presentation of the reaction. 

Substituents that serve as protectors are of value because they are removable. The critical feature of each protector is, therefore, how it is removed. Therefore, instead of discussing protectors on the basis of their constitution, the subject of protection is presented on the basis of the methods of deprotection, using the more common protectors as examples. 

KW Rosenmund, F Heise. Oxidative catalytic dehydrogenation of alcohols. V. Catalytic reduction of esters and aldehydes. Ber 54B 2038, 1921. 

V du Vigneaud, C Ressler, JM Swan, CW Roberts, PG Katsoyannis. The synthesis of oxytocin. J Am Chem Soc 76, 3115, 1954. 

J Pless, S Guttmann. New results concerning the protection of the guanido group, in HC Beyermann, A van de Linde, W Massen van den Brink, eds. Peptides. Proceedings of the 8th European Peptide Symposium. North-Holland, Amsterdam, 1967, pp 50-54. 

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