1280225-75-3Relevant academic research and scientific papers
3-Azaspiro[5,5]undecan-2,4-dioxo-3-yl diphenyl phosphate (ASUD-diphenyl phosphate), a new reagent for the synthesis of the N-protected amino acid-ASUD ester
Rao, B. Leelamaheswara,Nowshuddin, Shaik,Jha, Anjali,Divi, Murali K.,Rao
, p. 487 - 491 (2016/06/06)
A new reagent, 3-azaspiro[5,5]undecan-2,4-dioxo-3-yl diphenyl phosphate (ASUD-diphenyl phosphate) is described for the synthesis of N-protected amino acid-ASUD esters which are active esters useful in the synthesis of peptides. This compound was synthesized by reacting N-hydroxy-3-azaspiro[5,5]undecane-2,4-dione (HO-ASUD) with diphenyl chlorophosphate in the presence of a base at room temperature and was obtained in high yields. The ASUD-diphenyl phosphate reagent reacts with N-protected amino acids under mild conditions to give the corresponding ASUD active esters, while preserving the enantiomeric purity of the amino acid. The new reagent is a stable crystalline compound and eliminates the need for DCC, a potent skin allergen, used previously for the synthesis of N-protected amino acid-ASUD ester.
Synthesis of dipeptides from N-hydroxy-3-azaspiro[5,5]undecane-2,4-dione activated α-amino acids
Nowshuddin, Shaik,Ram Reddy
experimental part, p. 22 - 25 (2011/04/18)
A simple two step procedure for the synthesis of a dipeptide from N-hydroxy-3-azaspiro[5,5]undecane-2,4-dione (HO-ASUD) activated α-amino acids is described. In presence of DCC, N-hydroxy-3-azaspiro[5,5]undecane-2,4- dione readily esterifies the carboxylic acid group of all the N-protected amino acids to yield crystalline N-hydroxy-3-aza spiro[5,5]undecane-2,4-dione activated carboxy ester. The N-hydroxy-3-aza spiro[5,5]undecane-2,4-dione activated carboxy esters of N-protected amino acids readily condensed with other amino acids and gave a dipeptide. This new method is effective for the DCC coupling of a variety of chiral amino acids without loss of enantiomeric purity. Synthesis of fifteen dipeptides including the hitherto unreported Fmoc-l-Orn(Boc)-Val-OMe, Fmoc-l-Cys(trt)-Gly-OEt and Boc-l-Tyr-Gly-OEt is presented.
