(2R,3S)-1-[(tert-butyldimethylsilyl)oxy]-3-[(tert-butoxycarbonyl)amino]-4-cyclohexyl-2-[(p-nitrobenzoyl)oxy]butane

(2R,3S)- 3-(t-butoxycarbonylamino)-4-cyclohexyl-1,2-epoxybutane

(3S,4S)-3-hydroxy-4-<(tert-butyloxycarbonyl)amino>-5-cyclohexylpentanenitrile

(1S,2S)-1-(tert-butyldimethylsilyloxymethyl)-2-(tert-butoxycarbonylamino)-3-cyclohexylpropyl methanesulfonate