diethyl 2-pentylpropanedioate

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

Procedure: A solution of 29.4 g of 4-hydroxymethyl-1-p-ethoxyphenyl-1-nonanol [obtainable by reaction of diethyl 2-pentylmalonate (boiling point 127°/13 mbar) with ethyl 3-bromopropionate to give diethyl 2-carboethoxy-2-pentylglutarate (boiling point 160°/0.4 mbar), hydrolysis and decarboxylation to give 2-pentylglutaric acid, heating to form the anhydride (boiling point 120°/0.7 mbar), reaction with phenetol/AlCl3 to give 4-p-ethoxybenzoyl-2-pentylbutyric acid (m.p. 61°) and reduction with LiAlH4 ] and 1 g of p-toluenesulfonic acid in 400 ml of benzene is boiled under a water separator for 6 hours, then the mixture is washed with NaHCO3 solution, dried, evaporated and 2-p-ethoxyphenyl-5-pentyltetrahydropyran is obtained. to give

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

Procedure: A solution of 29.4 g of 4-hydroxymethyl-1-p-ethoxyphenyl-1-nonanol [obtainable by reaction of diethyl 2-pentylmalonate (boiling point 127°/13 mbar) with ethyl 3-bromopropionate to give diethyl 2-carboethoxy-2-pentylglutarate (boiling point 160°/0.4 mbar), hydrolysis and decarboxylation to give 2-pentylglutaric acid, heating to form the anhydride (boiling point 120°/0.7 mbar), reaction with phenetol/AlCl3 to give 4-p-ethoxybenzoyl-2-pentylbutyric acid (m.p. 61°) and reduction with LiAlH4 ] and 1 g of p-toluenesulfonic acid in 400 ml of benzene is boiled under a water separator for 6 hours, then the mixture is washed with NaHCO3 solution, dried, evaporated and 2-p-ethoxyphenyl-5-pentyltetrahydropyran is obtained. to give

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

Procedure: To a suspension of 60% sodium hydride (440 mg, 11 mmol) in 5 ml of dimethylformamide was added a solution of 2.30 g (10 mmol) of n-pentylmalonic acid diethyl ester in 5 m of dimethylformamide under stirring and ice cooling, and the resultant mixture was stirred for 30 minutes. A solution of 1.86 g (10 mmol) of 2, 3-dimethoxybenzyl chloride in 5 ml of dimethylformamide was dropwise added to the mixture, which was stirred at 70° C. for 1 hour. After cooling, the reaction mixture was mixed with water and extracted with ethyl acetate. The organic layers were combined, washed with water and saturated saline in this order, dried over anhydrous magnesium sulfate and the solvent evaporated in vacuo. The residue was chromatographed on a silica gel column, eluting with ethyl acetate/hexane (1/12) to give 2.78 g of 2, 3-dimethoxybenzyl-n-pentylmalonic acid diethyl ester as a colorless oil. Yield, 73%. was stirred at 70° C. for 1 hour After cooling extracted with ethyl acetate washed with water and saturated saline in this order dried over anhydrous magnesium sulfate the solvent evaporated in vacuo The residue was chromatographed on a silica gel column eluting with ethyl acetate/hexane (1/12)

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

Procedure: 34 g (0.9 mol) of LiAlH4 was dispersed in 690 cm3 of anhydrous THF, and 159 g (0.69 mol) of diethyl pentylmalonate was added dropwise under stirring. After the dropping was completed, it was refluxed for 2 hours in a hot water bath, and after cooling to room temperature, the excess LiAlH4 was decomposed by dropwise addition of THF including 10% water. 500 cm3 of concentrated hydrochloric acid was added, it was extracted with chloroform and washed in 10% HC1 and water. The chloroform was removed, and the remaining oily substance was distilled under reduced pressure (b. p. 110° C./4 mmHg) to obtain 76 g (0.52 mol) of 2-pentylpropane-1,3diol). it was refluxed for 2 hours in a hot water bath it was extracted with chloroform washed in 10% HC1 and water The chloroform was removed the remaining oily substance was distilled under reduced pressure (b. p. 110° C./4 mmHg)

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

Procedure: 35 g (0.92 mol) of lithium aluminum hydride was dispersed in 420 cm2 of anhydrous tetrahydrofuran (THF) and 193 g (0.84 mol) of diethyl pentylmalonate was added drop-wise to the dispersion while stirring at a speed to gently reflux the THF. The solution was refluxed and stirred for 3 hours. The product of the reaction was cooled with water and THF containing 10% water was added until the mixture ceased to foam. 500 cm2 of concentrated hydrochloric acid was added. The oily layer was separated and the water layer was extracted three times with 200 cm3 of ether. The oily layer and the ether layers were combined and washed with a saturated aqueous solution of sodium chloride. The ether layer was dried with anhydrous sodium sulfate and boiled to distil off the ether. The residue of the distillation was subjected to vacuum distillation (b.p. 120° C./2 Torrs) to yield 83 g (0.57 mol) of 2-pentylpropane-1,3-diol. was added drop-wise to the dispersion The solution was refluxed stirred for 3 hours was added until the mixture The oily layer was separated the water layer was extracted three times with 200 cm3 of ether washed with a saturated aqueous solution of sodium chloride The ether layer was dried with anhydrous sodium sulfate to distil off the ether The residue of the distillation was subjected to vacuum distillation (b.p. 120° C./2 Torrs)

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

Procedure: A solution of 29.4 g of 4-hydroxymethyl-1-p-ethoxyphenyl-1-nonanol [obtainable by reaction of diethyl 2-pentylmalonate (boiling point 127°/13 mbar) with ethyl 3-bromopropionate to give diethyl 2-carboethoxy-2-pentylglutarate (boiling point 160°/0.4 mbar), hydrolysis and decarboxylation to give 2-pentylglutaric acid, heating to form the anhydride (boiling point 120°/0.7 mbar), reaction with phenetol/AlCl3 to give 4-p-ethoxybenzoyl-2-pentylbutyric acid (m.p. 61°) and reduction with LiAlH4 ] and 1 g of p-toluenesulfonic acid in 400 ml of benzene is boiled under a water separator for 6 hours, then the mixture is washed with NaHCO3 solution, dried, evaporated and 2-p-ethoxyphenyl-5-pentyltetrahydropyran is obtained. to give