(8S,11S,14S)-3,18-dimethoxy-11-methyl-14-(methylamino)-10,13-dioxo-9,12-diazatricyclo[13.3.1.12,6]eicosane-1(19),2(20),3,5,15,17-hexaene-8-carboxylic acid methyl ester 、
2-[[(2R)-2-[[(2R)-2-[methyl(10-methylundecanoyl)amino]-3-phenylmethoxypropanoyl]amino]propanoyl]amino]acetic acid 在
3-(二乙氧基邻酰氧基)-1,2,3-苯并三嗪-4-酮 作用下,
以
四氢呋喃 为溶剂,
以83%的产率得到methyl (8S,11S,14S)-3,18-dimethoxy-11-methyl-14-[methyl-[2-[[(2R)-2-[[(2R)-2-[methyl(10-methylundecanoyl)amino]-3-phenylmethoxypropanoyl]amino]propanoyl]amino]acetyl]amino]-10,13-dioxo-9,12-diazatricyclo[13.3.1.12,6]icosa-1(18),2,4,6(20),15(19),16-hexaene-8-carboxylate