(4R,4'S)-4,4'-dimethyl-2'-phenyl-4,4',5,5'-tetrahydro-[2,4'-bithiazole]-4-carboxylic acid

methyl (4R,4'S,4''S)-4,4',4''-trimethyl-2''-phenyl-4,4',4'',5,5',5''-hexahydro-[2,4':2',4''-terthiazole]-4-carboxylate

(4R,4'S,4''S)-4,4',4''-trimethyl-2''-phenyl-4,4',4'',5,5',5''-hexahydro-[2,4':2',4''-terthiazole]-4-carboxylic acid

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