(R)-4-(tert-butoxy)-2-(1-methylethyl)-4-oxobutanoic acid

(R)-tert-butyl 3-hydroxymethyl-4-methylpentanoate

[(2R)-3-[[8-ethyl-4-[[4-(2-pyridyl)phenyl]methyl-amino]pyrazolo[1,5-a][1,3,5]triazin-2-yl]amino]-2-hydroxypropyl](2R)-2-bocamino-3-methylbutanoate