tert-butyl ((1S,2S)-2-((S)-2-((S)-2-(((benzyloxy)carbonyl)amino)propanamido)-3-phenylpropyl)cyclopropyl)carbamate

tert-butyl ((1S,2S)-2-((R)-2-((S)-2-(((benzyloxy)carbonyl)amino)propanamido)-4-phenylbutyl)cyclopropyl)carbamate

tert-butyl ((1S,2S)-2-((R)-2-((S)-2-(((benzyloxy)carbonyl)amino)propanamido)-5-phenylpentyl)cyclopropyl)carbamate

(2R,3S)-N-((1S,2S)-2-((R)-2-(2-naphthamido)-4-phenylbutyl)cyclopropyl)-3-((S)-sec-butyl)-4-oxooxetane-2-carboxamide

(2R,3S)-N-((1S,2S)-2-((R)-2-((S)-2-(2-naphthamido)propanamido)-4-phenylbutyl)cyclopropyl)-3-((S)-sec-butyl)-4-oxooxetane-2-carboxamide