trimethylsilyl (E)-but-2-enoate

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

Procedure: To a single-neck reaction flask (250 mL) were added (E)-trimethylsilyl 2-butenoate (12.242 g, 77.481 mmol), NBS (16.550 g, 92.977 mmol), (PhCO2)2 (310 mg) and carbon tetrachloride (100 mL). The mixture was stirred under reflux for 3.5 hr. The resulting mixture was cooled in an ice-water bath. The insoluble substance was filtered. The residue was rotatory-evaporated and concentrated until no liquid dropped. The concentrate was distilled under reduced pressure to collect the fraction under 9 mmHg at the temperature of 100° C.-102° C. to give the target compound as a colorless transparent liquid. under reflux for 3.5 hr The resulting mixture was cooled in an ice-water bath The insoluble substance was filtered The residue was rotatory-evaporated concentrated until no liquid dropped The concentrate was distilled under reduced pressure to collect the fraction under 9 mmHg at the temperature of 100° C.-102° C.

Conditions: temp:38.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a single-neck reaction flask (250 mL) were added of crotonic acid (10.750 g, 0.125 mol), anhydrous ethyl ether (125 mL) and trimethyl chlorosilane (19 mL, 0.150 mol). The mixture was stirred for 5 min. Pyridine (12 mL, 0.150 mol) was dropwise added into the resulting mixture under stirring at the temperature of 35° C. After the addition finished, the mixture was warmed up to the temperature of 38° C. and stirred under relux for 3 hr. The white solid was filtered in vacuo. Ethyl ether was evaporated under atmospheric pressure. The resultant was distilled under reduced pressure to collect the fraction under 10 mmHg at the temperature of 46° C.-48° C. to give (E)-trimethylsilyl 2-butenoate as a colorless liquid (12.242 g). Yield: 62.0%. under stirring at the temperature of 35° C After the addition stirred under relux for 3 hr The white solid was filtered in vacuo Ethyl ether was evaporated under atmospheric pressure The resultant was distilled under reduced pressure to collect the fraction under 10 mmHg at the temperature of 46° C.-48° C.

Conditions: temp:38.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a single-neck reaction flask (250 mL) were added of crotonic acid (10.750 g, 0.125 mol), anhydrous ethyl ether (125 mL) and trimethyl chlorosilane (19 mL, 0.150 mol). The mixture was stirred for 5 min. Pyridine (12 mL, 0.150 mol) was dropwise added into the resulting mixture under stirring at the temperature of 35° C. After the addition finished, the mixture was warmed up to the temperature of 38° C. and stirred under relux for 3 hr. The white solid was filtered in vacuo. Ethyl ether was evaporated under atmospheric pressure. The resultant was distilled under reduced pressure to collect the fraction under 10 mmHg at the temperature of 46° C.-48° C. to give (E)-trimethylsilyl 2-butenoate as a colorless liquid (12.242 g). Yield: 62.0%. under stirring at the temperature of 35° C After the addition stirred under relux for 3 hr The white solid was filtered in vacuo Ethyl ether was evaporated under atmospheric pressure The resultant was distilled under reduced pressure to collect the fraction under 10 mmHg at the temperature of 46° C.-48° C.

Conditions: temp:77.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A stirred mixture of trimethylsilylcrotonate (131 g, 0.828 mol), N-bromosuccinimide (206 g, 1.16 mol), benzoyl peroxide (3.41 g, 0.141 mol) and carbon tetrachloride (1 L) is warmed to reflux (77° C.) under visible light for 5 hours. The mixture is cooled to room temperature and the precipitated solid is removed by filtration. The filtrate is concentrated to a residue, which is distilled under reduced pressure. The product fractions are collected at 93–106° C. (9–15 mmHg) to give 127 g of the title compound (65%). GC-MS purity is 83–89%, 1HNMR is consistent with expected structure. is warmed The mixture is cooled to room temperature the precipitated solid is removed by filtration The filtrate is concentrated to a residue, which is distilled under reduced pressure The product fractions are collected at 93–106° C. (9–15 mmHg)

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

Procedure: Pyridine (138 g, 1.74 mol) is added dropwise to a stirred solution of crotonic acid (125 g, 1.45 mol), and chlorotrimethylsilane (189 g 1.74 mol) in ether (1.5 l) at room temperature. The reaction mixture is allowed to stir at room temperature overnight and the precipitate is removed by filtration. The filtrate is concentrated and the residue is distilled under reduced pressure. The product fraction is collected at 58–70° C. (25 mmHg) to give 180 g of the title compound (79%). GC-MS purity is 93.4%, 1HNMR is consistent with the structure. the precipitate is removed by filtration The filtrate is concentrated the residue is distilled under reduced pressure The product fraction is collected at 58–70° C. (25 mmHg)

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

Procedure: To a single-neck reaction flask (250 mL) were added (E)-trimethylsilyl 2-butenoate (12.242 g, 77.481 mmol), NBS (16.550 g, 92.977 mmol), (PhCO2)2 (310 mg) and carbon tetrachloride (100 mL). The mixture was stirred under reflux for 3.5 hr. The resulting mixture was cooled in an ice-water bath. The insoluble substance was filtered. The residue was rotatory-evaporated and concentrated until no liquid dropped. The concentrate was distilled under reduced pressure to collect the fraction under 9 mmHg at the temperature of 100° C.-102° C. to give the target compound as a colorless transparent liquid. under reflux for 3.5 hr The resulting mixture was cooled in an ice-water bath The insoluble substance was filtered The residue was rotatory-evaporated concentrated until no liquid dropped The concentrate was distilled under reduced pressure to collect the fraction under 9 mmHg at the temperature of 100° C.-102° C.

Conditions: temp:38.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a single-neck reaction flask (250 mL) were added of crotonic acid (10.750 g, 0.125 mol), anhydrous ethyl ether (125 mL) and trimethyl chlorosilane (19 mL, 0.150 mol). The mixture was stirred for 5 min. Pyridine (12 mL, 0.150 mol) was dropwise added into the resulting mixture under stirring at the temperature of 35° C. After the addition finished, the mixture was warmed up to the temperature of 38° C. and stirred under relux for 3 hr. The white solid was filtered in vacuo. Ethyl ether was evaporated under atmospheric pressure. The resultant was distilled under reduced pressure to collect the fraction under 10 mmHg at the temperature of 46° C.-48° C. to give (E)-trimethylsilyl 2-butenoate as a colorless liquid (12.242 g). Yield: 62.0%. under stirring at the temperature of 35° C After the addition stirred under relux for 3 hr The white solid was filtered in vacuo Ethyl ether was evaporated under atmospheric pressure The resultant was distilled under reduced pressure to collect the fraction under 10 mmHg at the temperature of 46° C.-48° C.