[formula: see text] The new crystalline phosphate reagent 3-(diethoxyphosphoryloxy)-1,2,3-benzotriazin-4(3H)-one (DEPBT) mediates amide bond formation with a remarkable resistance to racemization. Comparative racemization studies were carried out and DEPBT proved to be superior to typical phosphonium and uronium coupling reagents. DEPBT is easily prepared and is exceedingly stable with a shelf life
N-protected γ-amino-β-keto-esters were synthesized from the corresponding N-protected N-carboxyanhydride (UNCAs) by reaction with the lithium enolate of ethyl acetate in good yields. These compounds are precursors of statine derivatives.
Rapid, one-pot synthesis of urethane-protected tripeptides
作者:Yun-Fei Zhu、William D. Fuller
DOI:10.1016/0040-4039(94)02391-n
日期:1995.2
Urethane-protected tripeptides are synthesized in solution, without isolation or purification of intermediates, using urethane-protected N-carboxyanhydrides as coupling reagents and hydrogenation for removal of N-protection.