Cyclodipeptide (3 S,6S ) bis(phenylmethyl)piperazine 2,5 dione was prepared in high yield by heating phenylalanine methyl ester in toluene under reflux. The reduction of this cyclodipeptide with sodium NaBH 4 B...Cyclodipeptide (3 S,6S ) bis(phenylmethyl)piperazine 2,5 dione was prepared in high yield by heating phenylalanine methyl ester in toluene under reflux. The reduction of this cyclodipeptide with sodium NaBH 4 BF 3 in DME gave the (2 S,5S ) bis(phenylmethyl)piperazine, which, on heating with ethylene bromide and triethylamine, afforded the title compounds. This method was proved to be generally applicable to the synthesis of C 2 symmetric 2,5 disubstituted 1,4 diazabicyclo[2.2.2]octane from the corresponding natural or unnatural amino acid esters.展开更多
基金theNaturalScienceFoundationofJiangsuEducationOffice (No .0 1KJB15 0 0 0 2 )
文摘Cyclodipeptide (3 S,6S ) bis(phenylmethyl)piperazine 2,5 dione was prepared in high yield by heating phenylalanine methyl ester in toluene under reflux. The reduction of this cyclodipeptide with sodium NaBH 4 BF 3 in DME gave the (2 S,5S ) bis(phenylmethyl)piperazine, which, on heating with ethylene bromide and triethylamine, afforded the title compounds. This method was proved to be generally applicable to the synthesis of C 2 symmetric 2,5 disubstituted 1,4 diazabicyclo[2.2.2]octane from the corresponding natural or unnatural amino acid esters.
