S-((7R)-7-((tert-butyldimethylsilyl)oxy)-1-((3S,6R,9S,14aR)-6,9-dibenzyl-6-methyl-1,4,7,10-tetraoxotetradecahydropyrrolo[1,2-a][1,4,7,10]tetraazacyclododecin-3-yl)-6-oxooctan-3-yl) O-ethyl carbonodithioate

(-)-(R)-S-3-(tert-butyldimethylsilyloxy)-2-oxobutyl O-ethyl carbonodithioate

methyl 2-[(tert-butoxycarbonyl)amino]hex-5-enoate

(-)-(2S,4R)-3-benzoyl-4-benzyl-4-methyl-2-phenyl-1,3-oxazolidin-5-one