benzyl ((S)-1-(((S)-1-((1S,2S)-2-((2R,3S)-3-((S)-sec-butyl)-4-oxooxetane-2-carboxamido)cyclopropyl)-3-(naphthalen-1-yl)propan-2-yl)amino)-1-oxopropan-2-yl)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

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

(2R,3S)-N-((1S,2S)-2-((2R,3R)-3-(2-naphthamido)-5-phenylpentan-2-yl)cyclopropyl)-3-((S)-sec-butyl)-4-oxooxetane-2-carboxamide