tert-butyl (4S,5S)-4-isobutyl-5-((1R,2R)-2-(methoxycarbonyl)-4-(2-tosylhydrazineylidene)cyclopentyl)-2,2-dimethyloxazolidine-3-carboxylate

(5S)-tert-butoxycarbonylamino-(4S,R)-hydroxy-7-methyl-oct-2-ynoic acid methyl ester

(4S)-isobutyl-(5S)-(2-methoxycarbonyl-vinyl)-2,2-dimethyl-oxazolidine-3-carboxylic acid tert-butyl ester

(4S)-isobutyl-(5S)-((2R)-methoxycarbonyl-4-oxo-cyclopentyl)-2,2-dimethyl-oxazolidine-3-carboxylic acid tert-butyl ester

(4S)-isobutyl-(5S)-((2R)-methoxycarbonyl-cyclopentyl)-2,2-dimethyl-oxazolidine-3-carboxylic acid tert-butyl ester