((3S,5S)-5-Hydroxymethyl-3-methyl-2-oxo-pyrrolidin-3-yl)-carbamic acid tert-butyl ester

(+)-(4S,6S)-6-hydroxymethyl-6-methyl-1,4,5,6-tetrahydropyrimidine-4-carboxylic acid

((1S,3S)-3-tert-Butoxycarbonylamino-4-hydroxy-1-hydroxymethyl-3-methyl-butyl)-carbamic acid tert-butyl ester

di-tert-butyl ((3S,5S)-5-methyl-2-oxotetrahydro-2H-pyran-3,5-diyl)dicarbamate

(2S,4S)-2,4-Bis-tert-butoxycarbonylamino-5-hydroxy-2-methyl-pentanoic acid methyl ester