methyl (4R,4'S,4''S)-2''-((S)-2-((tert-butoxycarbonyl)amino)-1-mercaptopropan-2-yl)-4,4',4''-trimethyl-4,4',4'',5,5',5''-hexahydro-[2,4':2',4''-terthiazole]-4-carboxylate

methyl (4R,4'S,4''S,4'''S)-4,4',4'',4'''-tetramethyl-2'''-phenyl-4,4',4'',4''',5,5',5'',5'''-octahydro-[2,4':2',4'':2'',4'''-quaterthiazole]-4-carboxylate

(4R,4'S,4''S,4'''S)-4,4',4'',4'''-tetramethyl-2'''-phenyl-4,4',4'',4''',5,5',5'',5'''-octahydro-[2,4':2',4'':2'',4'''-quaterthiazole]-4-carboxylic acid

(4R)-4-methyl-2-phenyl-4,5-dihydrothiazole-4-carboxylic acid

N-Boc-methylcysteine methyl ester