Fmoc-Asp(OtBu)-OH [71989-14-5] HEADING_TITLE

N-Fmoc-L-aspartic acid beta-tert-butyl ester

Other Names: Fmoc-L-Asp(OtBu)-OH; N-Fmoc-L-aspartic acid β-t-butyl ester

Catalog # AFD105 CAS 71989-14-5
Formula C23H25NO6 M.W. 411.5









Fmoc-Asp(OtBu)-OH is the standard Fmoc-protected derivative of aspartic acid used in peptide synthesis. The t-butyl ester of the side chain is readily hydrolyzed in the same conditions used to cleave peptides from Wang resin or Rink amide resin. The t-butyl cations formed in the hydrolysis of the esters can produce byproducts by reattaching to nucleophilic residues in the peptide, so nucleophilic scavengers such as thiophenol and anisole should be added to the cleavage mixture when Fmoc-Asp(OtBu)-OH is utilized.

Fmoc-Asp(OtBu)-OH Side Reactions

The Asp(OtBu) residue can form aspartimide under strong basic conditions.  The aspartimide can open to form either the desired peptide or the beta-peptide.  Backbone protection on the amino acid before Asp will prevent aspartimide formation.  It has been reported that adding a small amount of formic acid to the piperidine solution used for Fmoc removal will suppress aspartimide formation (T. Michaels, et al., Org. Lett., 2012, 14, 5218).

Products Similar to Fmoc-Asp(OtBu)-OH

Cat. # Product Cat. # Product
AFD135 Fmoc-Asp(OAll)-OH ABD125 Boc-Asp(OtBu)-OH
AFD103 Fmoc-Asp(OBzl)-OH ABD130 Boc-Asp(OtBu)-OH DCHA
AFD130 Fmoc-Asp(OcHx)-OH ABD110 Boc-Asp(OBzl)-OH
AFD140 Fmoc-Asp(OMe)-OH ABD115 Boc-Asp(OcHx)-OH
AFD195 Fmoc-Asp(OtBu)-OPfp ABD113 Boc-Asp(OFm)-OH
AFD101 Fmoc-Asp-OH ABD140 Boc-Asp(OMe)-OH DCHA
AFD110 Fmoc-Asp-OAll ABD112 Boc-Asp(OBzl)-ONp
AFD115 Fmoc-Asp-OBzl ABD133 Boc-Asp-OtBu
AFD125 Fmoc-Asp-OFm ABD135 Boc-Asp-OBzl
AFD120 Fmoc-Asp-OMe ABD143 Boc-Asp-OMe
AFD126 Fmoc-Asp-OtBu ABD230 Boc-D-Asp(OtBu)-OH DCHA
AFD205 Fmoc-D-Asp(OtBu)-OH ABD210 Boc-D-Asp(OBzl)-OH
AFD235 Fmoc-D-Asp(OAll)-OH ABD215 Boc-D-Asp(OcHx)-OH
AFD201 Fmoc-D-Asp-OH ABD201 Boc-D-Asp-OH
AFD295 Fmoc-D-Asp(OtBu)-OPfp ABD235 Boc-D-Asp-OBzl
MFD105 Fmoc-MeAsp(OtBu)-OH UBD121 Boc-beta-HAsp(OBzl)-OH
DFD105 Fmoc-Aspartimol(OtBu) ABE125 Boc-Glu(OtBu)-OH
DFD205 Fmoc-D-Aspartimol(OtBu) ABE110 Boc-Glu(OBzl)-OH
UFD161 Fmoc-beta-HAsp(OtBu)-OH ABE118 Boc-Glu(OcHx)-OH
UFD261 Fmoc-D-beta-HAsp(OtBu)-OH ABE116 Boc-Glu(OcHx)-OH DCHA
AFE105 Fmoc-Glu(OtBu)-OH ABE130 Boc-Glu(OFm)-OH
AFE125 Fmoc-Glu(OAll)-OH ABE121 Boc-Glu(OMe)-OH
AFE110 Fmoc-Glu(OBzl)-OH ABE127 Boc-Glu(OtBu)-ONp
AFE130 Fmoc-Glu(ODmab)-OH ABE101 Boc-Glu-OH
AFE150 Fmoc-Glu(Edans)-OH ABE115 Boc-Glu-OtBu
AFE107 Fmoc-Glu(OMe)-OH ABE113 Boc-Glu-OBzl DCHA
AFE195 Fmoc-Glu(OtBu)-OPfp ABE225 Boc-D-Glu(OtBu)-OH
AFE101 Fmoc-Glu-OH ABE210 Boc-D-Glu(OBzl)-OH
AFE112 Fmoc-Glu-OtBu ABE211 Boc-D-Glu(OBzl)-OH DCHA
AFE120 Fmoc-Glu-OAll ABE216 Boc-D-Glu(OcHx)-OH
AFE115 Fmoc-Glu-OBzl ABE215 Boc-D-Glu(OMe)-OH DCHA
AFE111 Fmoc-Glu-OMe ABE212 Boc-D-Glu(OBzl)-OSu
AFE205 Fmoc-D-Glu(OtBu)-OH    
AFE201 Fmoc-D-Glu-OH    
AFE208 Fmoc-D-Glu-OtBu    
AFE295 Fmoc-D-Glu(OtBu)-OPfp    
UFE161 Fmoc-beta-HGlu(OtBu)-OH    
UFE110 Fmoc-Aad(OtBu)-OH