反应详情

In analogy to intermediate 44C, (S)-4-[[(S)-2-(3-chloro-4-trifluoromethyl-phenylamino)-propionyl]-(2,2-dimethoxy-ethyl)-amino]-5-methoxy-pentanoic acid tert-butyl ester was cyclized with trifluoroacetic acid/triethylsilane to give the titled compound in 36% yield as brown oil. MS: 421.2 (MH+, 1Cl).