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

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