Trimethylsilylacetylene → 1-Allyloxycarbonyl-4-hydroxy-2-methoxycarbonyl-4-trimethylsilylethynylpyrrolidine

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Reaction Steps

To a solution of trimethylsilylacetylene (5 g) in tetrahydrofuran (60 ml) was added n-butyllithium (32 ml) slowly and dropwise at -50° C. After completion of the dropwise addition, the mixture was stirred at -50° C. for 30 minutes, at the end of which time a tetrahydrofuran solution (10 ml) of (2S)-1-allyloxycarbonyl-2-methoxycarbonyl-4-oxopyrrolidine (10 g) was added below -50° C. The mixture was stirred for 1 hour and, then, diluted with saturated aqueous ammonium chloride solution and ethyl acetate. After standing, the aqueous layer was separated and extracted with ethyl acetate twice and the organic layers were combined, washed successively with 1N hydrochloric acid, saturated aqueous sodium hydrogen carbonate solution, water and aqueous sodium chloride solution and dried over anhydrous magnesium sulfate. Finally the solvent was distilled off under reduced pressure to give 1-allyloxycarbonyl-4-hydroxy-2-methoxycarbonyl-4-trimethylsilylethynylpyrrolidine (8.26 g).

Provenance & Evidence