Boc-Lys(Ac)-OH HCl

73548-77-3

55757-60-3

General procedure for the synthesis of (S)-6-amino-2-((tert-butoxycarbonyl)amino)hexanoic acid methyl ester from (S)-6-(((benzyloxy)carbonyl)amino)-2-((tert-butoxycarbonyl)amino)hexanoic acid: intermediate 4 (839 mg, 2.1 mmol) was dissolved in methanol (15 mL). After addition of catalytic amount of Pd/C, the reaction was stirred under hydrogen atmosphere and room temperature for 40 min. The completion of the reaction was monitored by thin-layer chromatography (TLC, unfolding reagent ratio of ethyl acetate:hexane = 2:1). After completion of the reaction, the reaction solution was filtered through a diatomaceous earth pad. The filtrate was concentrated under reduced pressure to give Intermediate 5 (563 mg, quantitative yield) as a colorless oil, which can be used in subsequent reactions without further purification.