2-tert-butoxycarbonyloxy-4-[3-(1-tert-butoxycarbonyl-1H-pyrrol-2-yl)-3-hydroxy-prop-1-ynyl]-5-fluoro-indole-1-carboxylic acid tert-butyl ester → 2-tert-Butoxycarbonyloxy-4-[3-(1-tert-butoxycarbonyl-1H-pyrrol-2-yl)-3-oxo-prop-1-ynyl]-5-fluoro-indole-1-carboxylic acid tert-butyl ester

Participants

Reaction Steps

To a solution of 2-tert-butoxycarbonyloxy-4-[3-(1-tert-butoxycarbonyl-1H-pyrrol-2-yl)-3-hydroxy-prop-1-ynyl]-5-fluoro-indole-1-carboxylic acid tert-butyl ester (from Example 3 above) (7.60 g, 13.3 mmol) in CH2Cl2 (400 ml) was added MnO2 (Aldrich, 11.5 g, 130 mmol) in one portion. The reaction mixture was stirred at room temperature overnight and then filtered through Celite® and the solid was washed with CH2Cl2 (200 mL). The combined filtrates was concentrated in vacuo. 2-tert-Butoxycarbonyloxy-4-[3-(1-tert-butoxycarbonyl-1H-pyrrol-2-yl)-3-oxo-prop-1-ynyl]-5-fluoro-indole-1-carboxylic acid tert-butyl ester was obtained as a light orange amorphous solid which was used in the next step without further purification. (Yield 7.0 g, 92.5%).

Provenance & Evidence