(4R)-3-[(tert-butoxy)carbonyl]-1,3-thiazolidine-4-carboxylic acid → (S)-2-((tert-butoxycarbonyl)amino)-6-((R)-3-(tert-butoxycarbonyl)thiazolidine-4-carboxamido)hexanoic acid

Participants

Reaction Steps

4-(4,6-Dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (247 mg, 0.892 mmol) was added to a solution of (R)-3-(tert-butoxycarbonyl)thiazolidine-4-carboxylic acid (Compound tk81) (208 mg, 0.892 mmol) in DMF (1 ml), and the mixture was stirred at room temperature for 30 minutes. A solution of (S)-6-amino-2-((tert-butoxycarbonyl)amino)hexanoic acid (220 mg, 0.892 mmol) in water (1 ml) was added dropwise at room temperature over 3 minutes. After completion of the dropwise addition, the mixture was stirred at room temperature for 30 minutes. The reaction solution was purified by reverse-phase silica gel column chromatography (10 mM aqueous ammonium acetate solution/methanol) to afford (S)-2-((tert-butoxycarbonyl)amino)-6-((R)-3-(tert-butoxycarbonyl)thiazolidine-4-carboxamido)hexanoic acid (Compound tk82) (156 mg, 38%).

Provenance & Evidence