3-[hydroxy-(1-triisopropylsilanyl-1H-indol-5-yl)-methyl]-3-phenyl-pyrrolidine-1-carboxylic acid methyl ester → 3-phenyl-3-(1-triisopropylsilanyl-1H-indole-5-carbonyl)-pyrrolidine-1-carboxylic acid methyl ester

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

Manganese dioxide (85%, 256 mg, 2.95 mmol) was added to a solution of 3-[hydroxy-(1-triisopropylsilanyl-1H-indol-5-yl)-methyl]-3-phenyl-pyrrolidine-1-carboxylic acid methyl ester (300 mg, 0.59 mmol) in toluene (8 mL). The reaction mixture was heated at 100° C. for 2 hours, then cooled to room temperature and filtered through a celite pad. The filtrate was evaporated under reduced pressure to give 326 mg of 3-phenyl-3-(1-triisopropylsilanyl-1H-indole-5-carbonyl)-pyrrolidine-1-carboxylic acid methyl ester as a colorless foamy oil. A portion of this product (298 mg, 0.59 mmol) was dissolved in THF (8 mL) and a solution of tetrabutylammonium fluoride (1.0 M in THF, 0.60 mL, 0.59 mmol) was added at 0° C. The reaction mixture was stirred at 0° C. for 20 minutes, then was quenched by addition of water. The resulting mixture was extracted with EtOAc, and the combined organic extracts were dried over MgSO4, filtered and evaporated under reduced pressure. The residue was purified by flash chromatography (30% to 50% of EtOAc in hexane) to give 167 mg (81% 2 steps yield) of 3-(1H-indole-5-carbonyl)-3-phenyl-pyrrolidine-1-carboxylic acid methyl ester as a white foam.

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