tert-butyl ((3R,4R,5S)-4-{[tert-butyl(dimethyl)silyl]oxy}-5-methylpiperidin-3-yl)carbamate

benzyl (3R,5S)-3-[(tert-butoxycarbonyl)amino]-5-methyl-4-oxopiperidine-1-carboxylate

benzyl (3R,4R,5S)-3-[(tert-butoxycarbonyl)amino]-4-hydroxy-4,5-dimethylpiperidine-1-carboxylate