(2S,3S,4R)-4-tert-Butoxycarbonylamino-3-hydroxy-2-methyl-pentanoic acid 2,4-dinitro-phenyl ester 、 以86%的产率得到[(1R,2R,3S)-3-((1S,2R)-1-{2-[4-(3-Bromo-propylcarbamoyl)-[2,4']bithiazolyl-2'-yl]-ethylcarbamoyl}-2-hydroxy-propylcarbamoyl)-2-hydroxy-1-methyl-butyl]-carbamic acid tert-butyl ester