N-benzyloxycarbonyl protecting groups

Knudsen, K.R.. Holden. J.. Ley. S.V.. and Ladlow, M. (2007) Optimisation of conditions for O-benzyl and N-benzyloxycarbonyl protecting group removal using an automated flow... 

To add a leucine residue to the N terminus of the ethyl ester of Z-Phe-Gly, the benzyloxycarbonyl protecting group must first be removed. This can be accomplished by hydrogenolysis. 

The tentative structure (83 4,4 -dioxo), previously proposed for homaline, has been confirmed by stereospecific synthesis of its degradation product, bis-dihydrodesoxohomaline (83) (Scheme 5). Arndt-Eistert homologation of N-benzyloxycarbonyl-D-phenylglycine (79) gave the ester (80), which upon N-methylation, removal of the benzyloxycarbonyl protective group, and hydrolysis... 

Protecting group abbreviations are as follows JV-benzyloxycarbonyl (Z), N-tert-butyloxycarbonyl (Boc), tert-butyl ether (Bu ), and S-tert-butyl (Bu ). 

In order to test the influence of the C-terminus protecting groups on the properties of the resulting polymer, the ethyl, hexyl, and palmityl esters of N-benzyloxycarbonyl-L-tyrosyl-L-tyrosine were synthesized and the corresponding polymers (poly(CTTE),... 

N-Acylation and 3-alkoxycarbonylation reactions may be achieved by conventional acylation procedures. A variety of 3-acyl derivatives 157 can be prepared most conveniently by the treatment of DPPOx 266 with carboxylic acids in the presence of a tertiary amine. tert-Butoxycarbonyl (Boc-Ox, 236) and benzyloxy carbonyl (Cbz-Ox, 267) (Cbz = benzyloxycarbonyl) compounds are of practical use for introduction of nitrogen protecting groups. ... 

The racemic mixture of Z-Gly-DL-Alap can be separated to give pure enantiomers by simple crystallization with enantiomeric a-methylbenzylaminesJ7] An example of the separation of enantiomers is given in Scheme 5 for the separation of Z-L-Ala-D-Ala and Z-L-Ala-D-Ala.[7] The N-terminal protecting benzyloxycarbonyl group is removed by standard hydrogenolysis on 5% Pd/C catalyst. 

---