mono[(1H-3-indol-3-yl)propyl] (3R,4R,5S)-4-acetamido-5-amino-3-(1-ethylpropoxy)-1-cyclohexene-1-phosphonate

monobutyl (3R,4R,5S)-4-acetamido-3-(1-ethylpropoxy)-5-guanidino-1-cyclohexene-1-phosphonate

mono(3-phenylpropyl) (3R,4R,5S)-4-acetamido-3-(1-ethylpropoxy)-5-guanidino-1-cyclohexene-1-phosphonate

diethyl (3R,4R,5S)-4-acetamido-5-tert-butoxycarbonylamino-3-(1-ethylpropoxy)cyclohex-1-ene-1-phosphonate