for the following products
Ethyl (S)-2-[(S)-4-methyl-2,5-dioxo-1,3-oxazolidin-3-yl]-4-phenylbutyrate | N-(1-(S)-(ethoxycarbonyl)-3-phenylpropyl)-L-alanyl-carboxy-anhydride and N-[1-(S)-Ethoxycarbonyl-3-phenylpropyl]-L-alanyl-N-carboxy anhydride (ECPPA-NCA)