(R)-Δ2-5-hydroxymethyl-5-methyl-3-pyrazolinecarboxylic acid ethyl ester

ethyl (2R)-4-(tert-butyldiphenylsilyloxymethyl)-2-hydroxy-4-pentenoate

(2R,4S)-2,4-Diamino-5-hydroxy-2-methyl-pentanoic acid

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

tert-butyl (3S,5R)-5-methyl-2-oxotetrahydro-2H-pyran-3,5-diyldicarbamate