di-tert-butyl 2-[4-((9S,10S,18S,14R)-7,16,19-triaza-9-{[(tert-butyl)oxycarbonyl]methyl}-18-(carbamoylmethyl)-14-[(5-methylindolyl)methyl]-8,17,20-trioxospiro[5.14]icos-11-en-10-yl)phenyl]propane-1,3-dioate 在
ethandithiol 、
三氟乙酸 作用下,
反应 1.1h,
以38%的产率得到2-{4-[(E)-(9S,10S,14R,18S)-18-Carbamoylmethyl-9-carboxymethyl-14-(5-methyl-indol-1-ylmethyl)-8,17,20-trioxo-7,16,19-triaza-spiro[5.14]icos-11-en-10-yl]-phenyl}-malonic acid