Trifluoroacetic acid → Fmoc-N-methyl-S-tert-butylthio-L-cysteine

Participants

Reaction Steps

Triethylsilane (6.04 ml, 37.8 mmol) and trifluoroacetic acid (9 ml) were added to a solution of (R)-(9H-fluoren-9-yl)methyl 4-((tert-butyldisulfanyl)methyl)-5-oxooxazolidine-3-carboxylate (Compound 2b-B) (1.68 g, 3.78 mmol) in dichloromethane (18 ml), and the mixture was stirred at room temperature for one day. The reaction mixture was then concentrated under reduced pressure, and the residue was purified by reverse-phase silica gel column chromatography (10 mM aqueous ammonium acetate solution/methanol=70/30→20/80→0/100) to afford (R)-2-((((9H-fluoren-9-yl)methoxy)carbonyl)(methyl)amino)-3-(tert-butyldisulfanyl)propanoic acid (Compound 2c-B) (1.22 g, 72%).

Provenance & Evidence