反应详情

190 mg (0.47 mmol) of 1-tert-Butyl 6-ethyl (2S)-2-[(tert-butoxycarbonyl)amino]-5-(3-hydroxypropyl)hexanedioate (5b) were dissolved in 10 mL dichloromethane at 0° C. Then, 284 mg (391 microL, 2.8 mmol) triethylamine and 179 mg (0.94 mmol) p-toluene sulfonyl chloride were added at 0° C. and the mixture was stirred at this temperature for 3 h. After stirring for 18 h at r.t. the solution was concentrated under reduced pressure and the residue was purified by column chromatography on silica gel (hexane/ethyl acetate gradient) to give (S)-2-tert-Butoxycarbonylamino-5-[3-(toluene-4-sulfonyloxy)-propyl]-hexanedioic acid 1-tert-butyl ester 6-ethyl ester as a colourless oil.

1. stirringAfter stirring for 18 h at r.t. the solution
2. concentrationwas concentrated under reduced pressure
3. customthe residue was purified by column chromatography on silica gel (hexane/ethyl acetate gradient)