ethyl 3-trimethylsilyloxybut-2-enoate

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of 31.9 mL (0.25 mole) of ethyl acetoacetate is stirred in hexane (350 mL) at room temperature. Triethylamine (42 mL, 0.30 mole) is added, followed by dropwise addition of trimethylsilyl chloride (35 mL, 0.276 mole) keeping the internal temperature below 25° C. using a water bath (about 18° C.). The thick white slurry is stirred overnight at room temperature. 200 mL of hexane is then added and the mixture stirred in an ice bath for 1 hour. The mixture is filtered and the solids are washed with 50 mL of cold hexane. Evaporation of the combined filtrate and washings gives 46 g of 3-trimethylsilanyloxy-but-2-enoic acid ethyl ester as a colorless, slightly cloudy oil. This material is used without further purification in the following step. the internal temperature below 25° C. (about 18° C.) the mixture stirred in an ice bath for 1 hour The mixture is filtered the solids are washed with 50 mL of cold hexane Evaporation of the combined filtrate and washings

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of 31.9 mL (0.25 mole) of ethyl acetoacetate is stirred in hexane (350 mL) at room temperature. Triethylamine (42 mL, 0.30 mole) is added, followed by dropwise addition of trimethylsilyl chloride (35 mL, 0.276 mole) keeping the internal temperature below 25° C. using a water bath (about 18° C.). The thick white slurry is stirred overnight at room temperature. 200 mL of hexane is then added and the mixture stirred in an ice bath for 1 hour. The mixture is filtered and the solids are washed with 50 mL of cold hexane. Evaporation of the combined filtrate and washings gives 46 g of 3-trimethylsilanyloxy-but-2-enoic acid ethyl ester as a colorless, slightly cloudy oil. This material is used without further purification in the following step. the internal temperature below 25° C. (about 18° C.) the mixture stirred in an ice bath for 1 hour The mixture is filtered the solids are washed with 50 mL of cold hexane Evaporation of the combined filtrate and washings

Conditions: temp:25.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 182.21 g (1.4 mol) of ethyl acetoacetate and 169.98 g (1.4 mol) of triethylamine were dissolved in a mixed solvent of 182 mL of tetrahydrofuran and 1.64 L of hexane under nitrogen atmosphere. To this solution, 167.3 g (1.54 mol) of trimethylsilyl chloride was added dropwise at a temperature of 21 to 45° C., and then the solution was stirred at 25° C. for 3 hours. The reaction mixture was cooled to 10° C., the reaction was ceased by adding 547 mL of water thereto and an organic layer was separated. The organic layer was washed two times with 273 mL of water, dried over 54.7 g of anhydrous magnesium sulfate, and then filtered. The solvent was evaporated to obtain 301.3 g (crude yield 106.4%) of 3-(trimethylsilyloxy) but-2-enoic acid ethyl ester. The reaction mixture was cooled to 10° C. an organic layer was separated The organic layer was washed two times with 273 mL of water dried over 54.7 g of anhydrous magnesium sulfate filtered The solvent was evaporated

Conditions: temp:0.00; pressure:0.00; stir: