Triphenylphosphine → (R)-1-[4-(4-fluoro-benzyloxy)-phenyl]-5-oxo-pyrrolidine-3-carboxylic acid methyl ester

Beteiligte Stoffe

Reaktionsschritte

A solution of 550 mg (4.3 mmol) of 4-fluoro-benzylalcohol and 1.27 g (4.7 mmol) of triphenylphosphine in 7 ml of tetrahydrofurane is added dropwise at 0° C. to a solution of 1.11 g (4.7 mmol) of (R)-1-(4-hydroxy-phenyl)-5-oxo-pyrrolidine-3-carboxylic acid methyl ester and 1.01 g (4.7 mmol) of diisopropyl azodicarboxylate in 11 ml of tetrahydrofurane. The mixture is left to warm to RT and stirring is continued for 18 hours. For the working-up, after addition of 2 g of silica gel the reaction mixture is evaporated under reduced pressure. For purification, the material obtained is chromatographed on silica gel using first a 2:1-mixture, then a 1:1-mixture of heptane and ethyl acetate as the eluent. There are obtained 1.39 g (95% of theory) of (R)-1-[4-(4-fluoro-benzyloxy)-phenyl]-5-oxo-pyrrolidine-3-carboxylic acid methyl ester as a white solid; MS: m/e=344 (M+H)+.

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