for the following products
(2R,3S)-N-tert-Butoxycarbonyl-3-phenyl isoserine methyl ester | Methyl (2R,3S)-2-Hydroxy-3-(N-tert-Butoxycarbonyl)amino-3-phenylpropionate | Methyl (2R,3S)-N-tert-Butoxycarbonyl-3-phenylisoserinate and (aR,bS)-beta-[[(1,1-dDmethylethoxy)carbonyl]amino]-alpha-hydroxy-benzenepropanoic acid methyl ester
