1,1-dimethylethyl (R)-2,5-diaza-5-(bromoacetyl)-9,9,10,10-tetramethyl-8-oxa-6-phenyl-9-silaundecanoate

(R)-2-Benzyl-4-((R)-2-hydroxy-1-phenyl-ethyl)-3-oxo-piperazine-1-carboxylic acid tert-butyl ester

(R)-2-Benzyl-4-((R)-2-hydroxy-1-phenyl-ethyl)-piperazine-1-carboxylic acid tert-butyl ester

(R)-2-Benzyl-4-((R)-2-methoxy-1-phenyl-ethyl)-piperazine-1-carboxylic acid tert-butyl ester