Process for preparing (1r,2s,5s)-n-[(1s)-3-amino-1-(cyclobutylmethyl)-2,3-dioxopropyl]-3-[(2s)-2-[[[(1,1-dimethylethyl)amino]-carbonyl]amino]-3,3-dimethyl-1-oxobutyl]-6,6-dimethyl-3-azabicyclo[3.1.0]hexane-2-carboxamide

1) A process for the provision of a compound of Formula I

• said process comprising:
• (i) coupling a tertiaryamine salt of the compound of Formula Ic
• with a compound selected from the salt compounds of Formulae Id and Id′,
• in the presence of at least one peptide coupling reagent and at least one reagent having a basic nitrogen atom selected from a tertiary amine, a tertiary amide, a morpholine compound and mixtures of two or more thereof;
• and
• (ii) when the salt compound selected in Step (i) is a compound of Formula Id′, oxidizing the compound Ic produced in Step (i) to yield the compound of Formula I.