ethyl 3-formyl-2,2-dimethylcyclopropane-1-carboxylate

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: 64.5 g of a 15% strength solution of butyl-lithium in n-hexane were added dropwise to a suspension of 68.3 g (0.15 mol) of n-octyl-triphenylphosphonium bromide in 300 ml of absolute tetrahydrofuran at 0°-5° C., with the exclusion of air. After one hour, 25.5 g (0.15 mol) of ethyl 2-formyl-3,3-dimethylcyclopropanecarboxylate were slowly added, and the mixture was further stirred for 18 hours at room temperature. The mixture was shaken after the addition of 400 ml of toluene and 300 ml of water, the water was separated off and the organic phase was washed once again with 200 ml of water. The toluene solution was then dried over sodium sulphate and the solvent was distilled off in vacuo. The residue was stirred with 300 ml of petroleum ether (40°-60° C.), the solution was filtered off from the undissolved triphenylphosphine oxide, and the filtrate was again concentrated by evaporation in vacuo. The residue was distilled in vacuo. 22.6 g (57% of theory) of ethyl 2-(1-nonen-1-yl)-3,3-dimethylcyclopropanecarboxylate with a boiling point of 90° C./0.01 mm Hg were thus obtained. The mixture was shaken the water was separated off the organic phase was washed once again with 200 ml of water The toluene solution was then dried over sodium sulphate the solvent was distilled off in vacuo The residue was stirred with 300 ml of petroleum ether (40°-60° C.) the solution was filtered off from the undissolved triphenylphosphine oxide the filtrate was again concentrated by evaporation in vacuo The residue was distilled in vacuo

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

Procedure: Phenylacetonitrile is added to a stirred solution of sodium ethoxide in absolute ethanol (prepared from 1.1 g sodium and 100 ml of ethanol). Next, a solution of 3-formyl-2,2-dimethyl-cyclopropanecarboxylic acid ethyl ester (8.5 g) in absolute ethanol (15 ml) is added over 5 minutes. The reaction mixture is stirred for 12 hours at room temperature and then heated on a steam bath for 0.5 hour. The alcohol is removed in vacuo, and the residue washed with water (250 ml) and ether (150 ml). The aqueous layer is acidified with concentrated hydrochloric acid. The resulting cream colored slurry is filtered and the isolated product dried. The product is dissolved in ether and precipitated with hexane to afford 6.1 g of white crystals, m.p. 186°-188° C. heated on a steam bath for 0.5 hour The alcohol is removed in vacuo the residue washed with water (250 ml) and ether (150 ml) is filtered the isolated product dried The product is dissolved in ether precipitated with hexane

Conditions: temp:-70.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 26.3 g (0.1 mol) of 4-chlorobenzyl-phosphonic acid diethyl ester were dissolved in 400 ml of absolute tetrahydrofuran and the solution was cooled to -70° C. 0.11 mol of n-butyl-lithium (15% strength solution in hexane) were added dropwise, in counter-current with nitrogen and while stirring thoroughly, and the reaction mixture was then subsequently stirred at -70° C. for a further 15 minutes. 15.4 g (0.1 mol) of carbon tetrachloride were then added dropwise at -70° C., also under nitrogen, and the reaction mixture thereby became red-brown in color. After stirring for a further 15 minutes, 18.6 g (0.1 mol) of 2,2-dimethyl-3-formyl-cyclopropanecarboxylic acid ethyl ester were added at -65° C. The reaction mixture was then allowed to come to room temperature and was subsequently stirred at 25° C. for a further 3 hours. The reaction mixture was then poured into 2 liters of water and extracted with 600 ml of ether. The ether phase was dried over sodium sulphate, the solvent was stripped off in vacuo and the oily residue was distilled at 150°-155° C./2 mm Hg. 2,2-Dimethyl-3-(2-chloro-2-p-chlorophenyl-vinyl)-cyclopropanecarboxylic acid ethyl ester was obtained in 54.3% yield. the reaction mixture was then subsequently stirred at -70° C. for a further 15 minutes After stirring for a further 15 minutes to come to room temperature was subsequently stirred at 25° C. for a further 3 hours extracted with 600 ml of ether The ether phase was dried over sodium sulphate the oily residue was distilled at 150°-155° C./2 mm Hg

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

Procedure: Phenylacetonitrile is added to a stirred solution of sodium ethoxide in absolute ethanol (prepared from 1.1 g sodium and 100 ml of ethanol). Next, a solution of 3-formyl-2,2-dimethyl-cyclopropanecarboxylic acid ethyl ester (8.5 g) in absolute ethanol (15 ml) is added over 5 minutes. The reaction mixture is stirred for 12 hours at room temperature and then heated on a steam bath for 0.5 hour. The alcohol is removed in vacuo, and the residue washed with water (250 ml) and ether (150 ml). The aqueous layer is acidified with concentrated hydrochloric acid. The resulting cream colored slurry is filtered and the isolated product dried. The product is dissolved in ether and precipitated with hexane to afford 6.1 g of white crystals, m.p. 186°-188° C. heated on a steam bath for 0.5 hour The alcohol is removed in vacuo the residue washed with water (250 ml) and ether (150 ml) is filtered the isolated product dried The product is dissolved in ether precipitated with hexane

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

Procedure: Phenylacetonitrile is added to a stirred solution of sodium ethoxide in absolute ethanol (prepared from 1.1 g sodium and 100 ml of ethanol). Next, a solution of 3-formyl-2,2-dimethyl-cyclopropanecarboxylic acid ethyl ester (8.5 g) in absolute ethanol (15 ml) is added over 5 minutes. The reaction mixture is stirred for 12 hours at room temperature and then heated on a steam bath for 0.5 hour. The alcohol is removed in vacuo, and the residue washed with water (250 ml) and ether (150 ml). The aqueous layer is acidified with concentrated hydrochloric acid. The resulting cream colored slurry is filtered and the isolated product dried. The product is dissolved in ether and precipitated with hexane to afford 6.1 g of white crystals, m.p. 186°-188° C. heated on a steam bath for 0.5 hour The alcohol is removed in vacuo the residue washed with water (250 ml) and ether (150 ml) is filtered the isolated product dried The product is dissolved in ether precipitated with hexane

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

Procedure: 64.5 g of a 15% strength solution of butyl-lithium in n-hexane were added dropwise to a suspension of 68.3 g (0.15 mol) of n-octyl-triphenylphosphonium bromide in 300 ml of absolute tetrahydrofuran at 0°-5° C., with the exclusion of air. After one hour, 25.5 g (0.15 mol) of ethyl 2-formyl-3,3-dimethylcyclopropanecarboxylate were slowly added, and the mixture was further stirred for 18 hours at room temperature. The mixture was shaken after the addition of 400 ml of toluene and 300 ml of water, the water was separated off and the organic phase was washed once again with 200 ml of water. The toluene solution was then dried over sodium sulphate and the solvent was distilled off in vacuo. The residue was stirred with 300 ml of petroleum ether (40°-60° C.), the solution was filtered off from the undissolved triphenylphosphine oxide, and the filtrate was again concentrated by evaporation in vacuo. The residue was distilled in vacuo. 22.6 g (57% of theory) of ethyl 2-(1-nonen-1-yl)-3,3-dimethylcyclopropanecarboxylate with a boiling point of 90° C./0.01 mm Hg were thus obtained. The mixture was shaken the water was separated off the organic phase was washed once again with 200 ml of water The toluene solution was then dried over sodium sulphate the solvent was distilled off in vacuo The residue was stirred with 300 ml of petroleum ether (40°-60° C.) the solution was filtered off from the undissolved triphenylphosphine oxide the filtrate was again concentrated by evaporation in vacuo The residue was distilled in vacuo

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

Procedure: 64.5 g of a 15% strength solution of butyl-lithium in n-hexane were added dropwise to a suspension of 68.3 g (0.15 mol) of n-octyl-triphenylphosphonium bromide in 300 ml of absolute tetrahydrofuran at 0°-5° C., with the exclusion of air. After one hour, 25.5 g (0.15 mol) of ethyl 2-formyl-3,3-dimethylcyclopropanecarboxylate were slowly added, and the mixture was further stirred for 18 hours at room temperature. The mixture was shaken after the addition of 400 ml of toluene and 300 ml of water, the water was separated off and the organic phase was washed once again with 200 ml of water. The toluene solution was then dried over sodium sulphate and the solvent was distilled off in vacuo. The residue was stirred with 300 ml of petroleum ether (40°-60° C.), the solution was filtered off from the undissolved triphenylphosphine oxide, and the filtrate was again concentrated by evaporation in vacuo. The residue was distilled in vacuo. 22.6 g (57% of theory) of ethyl 2-(1-nonen-1-yl)-3,3-dimethylcyclopropanecarboxylate with a boiling point of 90° C./0.01 mm Hg were thus obtained. The mixture was shaken the water was separated off the organic phase was washed once again with 200 ml of water The toluene solution was then dried over sodium sulphate the solvent was distilled off in vacuo The residue was stirred with 300 ml of petroleum ether (40°-60° C.) the solution was filtered off from the undissolved triphenylphosphine oxide the filtrate was again concentrated by evaporation in vacuo The residue was distilled in vacuo

Conditions: temp:-70.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 22.8 g (0.1 mol) of benzylphosphonic acid diethyl ester were dissolved in 400 ml of absolute tetrahydrofuran and the solution was cooled to -70° C. 0.11 mol of n-butyl-lithium (as a 15% strength solution in hexane) were added dropwise under a counter-current of nitrogen and while stirring well; the mixture was then stirred at -70° C. for a further 15 minutes, and thereafter 18.6 g (0.1 mol) of 2,2-dimethyl-3-formyl-cyclopropanecarboxylic acid ethyl ester were added dropwise at -65° C., again still under nitrogen. The reaction mixture was then allowed to come to room temperature and was stirred further for 3 hours at 25° C. Thereafter, the reaction batch was poured into 2 liters of water and extracted with 600 ml of ether. The ether phase was dried over sodium sulphate and the solvent was then stripped off in vacuo. The oily residue was distilled at 145°-150° C./3 mm Hg. 2,2 -Dimethyl-3-(2-phenyl-vinyl)-cyclopropanecarboxylic acid ethyl ester having a refractive index nD23 of 1.5022 was obtained in 69.6% yield. the mixture was then stirred at -70° C. for a further 15 minutes to come to room temperature was stirred further for 3 hours at 25° C extracted with 600 ml of ether The ether phase was dried over sodium sulphate The oily residue was distilled at 145°-150° C./3 mm Hg