(1R,2R)-N-(2-hydroxy-1-hydroxymethyl-2-methyl-but-3-ynyl)-2-nitrobenzenesulfonamide

(2S,3R)-3-(3-acetoxy-4-benzyloxyphenyl)-2-(tert-butoxycarbonylmethylamino)-3-hydroxypropionic acid methyl ester

(4S,5R)-3-(3-acetoxy-4-benzyloxyphenyl)-3-hydroxy-2-methylaminopropionic acid methyl ester

(R)-4-((R)-1-hydroxy-1-methylprop-2-ynyl)-2,2-dimethyl-oxazolidine-3-carboxylic acid tert-butyl ester

(2S,3R)-3-hydroxy-3-methyl-2-(2-nitro-benzenesulfonyl-amino)-pent-4-ynoic acid