ethyl 2-cyclopropylideneacetate

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

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

Conditions: temp:130.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 2-(Trimethylsiloxy)-1,3-butadiene (900 mg, 6.33 mmol) and ethyl cyclopropylideneacetate (2195 mg, 17.40 mmol) were combined in toluene (3 ml) and heated to 130° C. for 14 h. The mixture was then allowed to cool to room temperature and concentrated in vacuo to yield ethyl 7-[(trimethylsilyl)oxy]spiro[2.5]oct-6-ene-4-carboxylate that was used without further purification in the subsequent reaction. to cool to room temperature concentrated in vacuo

Conditions: temp:130.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 2-(Trimethylsiloxy)-1,3-butadiene (900 mg, 6.33 mmol) and ethyl cyclopropylideneacetate (2195 mg, 17.40 mmol) were combined in toluene (3 ml) and heated to 130° C. for 14 h. The mixture was then allowed to cool to room temperature and concentrated in vacuo to yield ethyl 7-[(trimethylsilyl)oxy]spiro[2.5]oct-6-ene-4-carboxylate that was used without further purification in the subsequent reaction. to cool to room temperature concentrated in vacuo

Conditions: temp:130.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 2-(Trimethylsiloxy)-1,3-butadiene (900 mg, 6.33 mmol) and ethyl cyclopropylideneacetate (2195 mg, 17.40 mmol) were combined in toluene (3 ml) and heated to 130° C. for 14 h. The mixture was then allowed to cool to room temperature and concentrated in vacuo to yield ethyl 7-[(trimethylsilyl)oxy]spiro[2.5]oct-6-ene-4-carboxylate that was used without further purification in the subsequent reaction. to cool to room temperature concentrated in vacuo

Conditions: temp:130.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 2-(Trimethylsiloxy)-1,3-butadiene (900 mg, 6.33 mmol) and ethyl cyclopropylideneacetate (2195 mg, 17.40 mmol) were combined in toluene (3 ml) and heated to 130° C. for 14 h. The mixture was then allowed to cool to room temperature and concentrated in vacuo to yield ethyl 7-[(trimethylsilyl)oxy]spiro[2.5]oct-6-ene-4-carboxylate that was used without further purification in the subsequent reaction. to cool to room temperature concentrated in vacuo

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

Conditions: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Under argon, 0.55 g (5.53 mmol) of copper(I) chloride and 0.59 g (13.82 mmol) of lithium chloride are suspended in 150 ml of anhydrous THF. The reaction mixture is cooled to −78° C., 48.8 ml (82.95 mmol) of vinylmagnesium chloride solution (1.7 M in THF) are added and the mixture is stirred for 10 minutes. Over a period of 30 min, a solution of 8.72 g (69.12 mmol) of ethyl cyclopropylideneacetate (Example 1A) in 50 ml of anhydrous THF is then added dropwise. After the addition is ended, the cooling bath is replaced by an ice/acetone bath. After a further 15 min, the reaction is terminated by dropwise addition of 100 ml of 1 N hydrochloric acid. The reaction mixture is saturated with sodium chloride, and 100 ml of a saturated sodium chloride solution which contains 5 ml of a 25% strength aqueous ammonia solution are then added. The mixture is filtered through Celite. The filtrate is washed with ammoniacal sodium chloride solution until the aqueous phase remains colorless. The organic phase is washed with saturated sodium chloride solution and dried over anhydrous magnesium sulfate. Removal of the solvent and kugelrohr distillation of the residue at 150° C. and 15 mbar gives 7.10 g (67% of theory) of the title compound as a colorless liquid. Over a period of 30 min After the addition the cooling bath is replaced by an ice/acetone bath After a further 15 min the reaction is terminated by dropwise addition of 100 ml of 1 N hydrochloric acid are then added The mixture is filtered through Celite The filtrate is washed with ammoniacal sodium chloride solution until the aqueous phase The organic phase is washed with saturated sodium chloride solution dried over anhydrous magnesium sulfate Removal of the solvent and kugelrohr distillation of the residue at 150° C.

Conditions: temp:90.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A suspension of 38.49 g (220.80 mmol) of [(1-ethoxycyclopropyl)oxy](trimethyl)silane, 100.0 g (287.04 mmol) of ethyl (triphenylphosphoranylidene)acetate and 3.51 g (28.70 mmol) of benzoic acid in 600 ml of toluene is stirred at a bath temperature of 90° C. for 18 hours. After cooling, the mixture is poured onto 800 g of silica gel 60 and eluted successively with in each case 3 liters of petroleum ether 40-60 and dichloromethane. The dichloromethane eluate is, after removal of the solvent, distilled at 160° C. and 14 mbar in a kugelrohr. This gives 17.95 g (64% of theory) of the title compound as a colorless liquid. After cooling the mixture is poured onto 800 g of silica gel 60 eluted successively with in each case 3 liters of petroleum ether 40-60 and dichloromethane after removal of the solvent distilled at 160° C.

Conditions: temp:130.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 2-(Trimethylsiloxy)-1,3-butadiene (900 mg, 6.33 mmol) and ethyl cyclopropylideneacetate (2195 mg, 17.40 mmol) were combined in toluene (3 ml) and heated to 130° C. for 14 h. The mixture was then allowed to cool to room temperature and concentrated in vacuo to yield ethyl 7-[(trimethylsilyl)oxy]spiro[2.5]oct-6-ene-4-carboxylate that was used without further purification in the subsequent reaction. to cool to room temperature concentrated in vacuo

Conditions: temp:130.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 2-(Trimethylsiloxy)-1,3-butadiene (900 mg, 6.33 mmol) and ethyl cyclopropylideneacetate (2195 mg, 17.40 mmol) were combined in toluene (3 ml) and heated to 130° C. for 14 h. The mixture was then allowed to cool to room temperature and concentrated in vacuo to yield ethyl 7-[(trimethylsilyl)oxy]spiro[2.5]oct-6-ene-4-carboxylate that was used without further purification in the subsequent reaction. to cool to room temperature concentrated in vacuo