Di-tert-butyl (2S)-2-[(tert-butoxycarbonyl)amino]-5-(4-hydroxybenzyl)hexanedioate → (2S)-2-amino-5-(4-hydroxybenzyl)hexanedioic acid

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Reaction Steps

1.56 g (3.25 mmol) (2S)-2-tert.-Butoxycarbonylamino-5-(4-hydroxy-benzyl)-hexanedioic acid di-tert.-butyl ester (Example 41b) were purified by chiral HPLC (Chiralpak AD-H 5 μm 250×300 mm; hexan/2-propanol; 40 mL7 min). Two isomers were isolated (isomer 1: 362 mg and isomer 2: 424 mg). 0.15 g (0.31 mmol) isomer 1 and 0.15 g (0.31 mmol) isomer 2 were individually deprotected according to the procedure described in Example 41c, yielding 42 mg (51%) (2S)-2-amino-5-(4-hydroxybenzyl)hexanedioic acid—Isomers C5-1 and 40 mg (48%) (2S)-2-amino-5-(4-hydroxybenzyl)hexanedioic acid—Isomers C5-2.

Provenance & Evidence