(R,E)-2-((((9H-Fluoren-9-yl)methoxy)carbonyl)amino)-3-(3-(tert-butoxycarbonyl)-2-((2,2,4,6,7-pentamethyl-2,3-dihydrobenzofuran-5-yl)sulfonyl)guanidino)propanoic acid 1g

(R,E)-2-((((9H-Fluoren-9-yl)methoxy)carbonyl)amino)-3-(3-(tert-butoxycarbonyl)-2-((2,2,4,6,7-pentamethyl-2,3-dihydrobenzofuran-5-yl)sulfonyl)guanidino)propanoic acid 1g