dimethyl butanedioate

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:50.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of dimethyl succinate (730 mg, 5.0 mmol) and 4-(tert-butyl-dimethyl-silanyloxy)-cyclohexanecarbaldehyde (1.00 g, 4.1 mmol) was added over 25 min to a 1.0M solution of potassium tert-butoxide in tert-butanol (4.4 mL. 4.4 mmol). The reaction mixture was heated at 50° C. for 50 min, cooled to RT and concentrated under vacuum. The residue was dissolved in water (25 mL) and washed with EtOAc (2×10 mL). The aqueous layer was acidified with 6 N HCl (2.0 mL, 12 mmol) and extracted with EtOAc (2×20 mL), dried (Na2SO4) and concentrated. The crude product was purified by flash chromatography (25% EtOAc/DCM) to give the title compound (560 mg) as a mixture of olefin isomers (˜1:1) and a mixture of cis and trans isomers at the cyclohexyl ring (˜1:1). 1H NMR (CDCl3, 400 mHz) δ (ppm) olefin peaks at 6.88 (d, J=10.2 Hz) 6.77 (d, J=10.0 Hz) CHOTBS peaks at 3.96 ppm (br s) (cis isomer, hydrogen equitorial, 3.55 (m) (trans isomer, hydrogen axial). cooled to RT concentrated under vacuum The residue was dissolved in water (25 mL) washed with EtOAc (2×10 mL) extracted with EtOAc (2×20 mL) dried (Na2SO4) concentrated The crude product was purified by flash chromatography (25% EtOAc/DCM)

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

Procedure: 1.60 g of 2,4-bis-[N-ethyl-N-(2,2,6,6-tetramethyl-4-piperidyl)amino]-6-(2-hydroxyethoxy)-1,3,5-triazine [prepared as described in Preparation 3(B)] and 0.22 g of dimethyl succinate were dissolved in 20 ml of toluene, and a catalytic amount of tetraisopropyl titanate was added to the resulting solution. The resulting mixture was first agitated at 100° to 105° C. for 3 hours whilst the methanol generated was removed by distillation, and then the temperature was elevated to 130° C. to remove the toluene. When this removal was complete, a mixture of ethyl acetate and water was added to the residue, and then the mixture was shaken. The ethyl acetate layer was then separated, dried and concentrated by evaporation under reduced pressure, and the resulting residue was purified by silica gel column chromatography (using a 10:3:1 by volume mixture of diethyl ether, ethanol and triethylamine as eluent), to obtain 920 mg of the title compound as crystals melting at 85° C. generated was removed by distillation was elevated to 130° C. to remove the toluene When this removal a mixture of ethyl acetate and water was added to the residue The ethyl acetate layer was then separated dried concentrated by evaporation under reduced pressure the resulting residue was purified by silica gel column chromatography ( by volume mixture of diethyl ether, ethanol and triethylamine as eluent),

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

Procedure: 700 mmol of dimethyl succinate and then 20 ml of methanol are added to 290 mmol of sodium methylate dissolved in 80 ml of methanol. The mixture is brought to reflux, and 236 mmol of benzaldehyde are slowly added, followed by 20 ml of methanol. The mixture is maintained at reflux, with stirring, for one hour, and then 100 ml of methanol are distilled off. 120 ml of water and 120 ml of 10N sodium hydroxide solution are added to the concentrated reaction mixture. The removal of the methanol by distillation is continued. The residue is diluted with 150 ml of water. After the addition of dichloromethane, the diacid is precipitated by the slow addition of 12N hydrochloric acid. The diacid is filtered and washed with dicliloromethane and then with water. Drying yields the expected product. to reflux The mixture is maintained at reflux 100 ml of methanol are distilled off 120 ml of water and 120 ml of 10N sodium hydroxide solution are added to the concentrated reaction mixture The removal of the methanol by distillation The residue is diluted with 150 ml of water After the addition of dichloromethane the diacid is precipitated by the slow addition of 12N hydrochloric acid The diacid is filtered washed with dicliloromethane Drying

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

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

Procedure: To a refluxing mixture of potassium tert-butoxide (27 g, 242 mmol) and tert-butanol (150 mL) was added a solution of 4-fluoro-benzaldehyde (20 g, 161 mmol) and dimethyl succinate (28 g, 193.2 mmol) in tert-butanol (100 mL) dropwise. After being heated at reflux for 3 hours, the mixture was concentrated in vacuo to remove tert-butanol. The residue was dissolved in 1 N hydrochloric acid (180 mL). The resulting aqueous solution was extracted with ethyl acetate (100 mL×3). The combined organic layers were dried over sodium sulfate, and concentrated in vacuo. The residue was purified by column chromatography (elution with 30% ethyl acetate in petroleum ether) to afford 2-(4-fluoro-benzylidene)-succinic acid 1-methyl ester (25.5 g, 66%) as a light yellow solid. 1H NMR (400 MHz, CD3OD) δ ppm 7.84 (s, 1H), 7.41-7.46 (m, 2H), 7.13-7.20 (m, 2H), 3.81 (s, 3H), 3.49 (s, 2H). After being heated at reflux for 3 hours the mixture was concentrated in vacuo to remove tert-butanol The residue was dissolved in 1 N hydrochloric acid (180 mL) The resulting aqueous solution was extracted with ethyl acetate (100 mL×3) The combined organic layers were dried over sodium sulfate concentrated in vacuo The residue was purified by column chromatography (elution with 30% ethyl acetate in petroleum ether)

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

Procedure: 322.3 g (2.05 mol) of 4-hydroxy-2,2,6,6-tetramethylpiperidine and 146.1 g (1 mol) of dimethyl succinate in 300 ml of xylene are heated to 80° C. 1.2 g of lithium amide are added to the reaction mixture at this temperature, and the temperature is raised to 120°-125° C. A mixture of methanol and xylene is then distilled off slowly under a slow stream of nitrogen. After approx. 10 hours virtually no more methanol distills off, which indicates the end of the transesterification. The contents of the flask are diluted with 500 ml of petroleum ether (boiling range 110°-140° C.) and are washed in the separating funnel while still warm (60°-70° C.) with three times 100 ml of water. The reaction product crystallizes from the organic phase on cooling as colourless crystals. The di-(2,2,6,6-tetramethyl-4-piperidinyl) succinate obtained melts at 118° C. the temperature is raised to 120°-125° C is then distilled off slowly under a slow stream of nitrogen After approx. 10 hours virtually no more methanol distills off The contents of the flask are diluted with 500 ml of petroleum ether (boiling range 110°-140° C.) are washed in the separating funnel while still warm (60°-70° C.) with three times 100 ml of water The reaction product crystallizes from the organic phase on cooling as colourless crystals

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

Procedure: 3 500 g of electrolyte containing 9.4% of furan, 40% of dimethyl maleate, 1% of NaBr and 49.6% of methanol were electrolyzed at 19-24° C. using a current of 5 A until the charge input was 1.1 F with respect to dimethyl maleate (which corresponds to 2.4 F with respect to furan). The effluent contained the products, furan and dimethoxyfurans, in a ratio of 1.0:9.3, which corresponds to a conversion of 90%. The selectivity to dimethoxydihydrofuran/dimethoxytetrahydrofuran was 99%. Dimethyl maleate conversion was more than 99%. Tetramethyl butanetetracarboxylate and dimethyl succinate were formed in a ratio of 1:0.31 and tetramethyl butanetetracarboxylate and methoxysuccinic acid in a ratio of 1:1.15. were electrolyzed at 19-24° C.

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

Procedure: Potassium tert-butoxide (14.2 g) is dissolved in tert-butyl alcohol (120 ml), and thereto is added dropwise a solution of 3,5-dimethoxybenzaldehyde (20 g) and dimethyl succinate (21.1 g) in tetrahydrofuran. The mixture is stirred at room temperature for 30 minutes, and water and isopropyl ether are added to the mixture. The aqueous layer is separated, and the remaining organic layer is further extracted with water. The aqueous layers are combined, and the pH value thereof is adjusted to pH 2-3 with conc. hydrochloric acid. The resulting oily product is extracted with ethyl acetate, and the extract is dried, concentrated under reduced pressure to give 4-(3,5-dimethoxyphenyl)-3-carboxy-3-butenoic acid methyl ester (42 g) as an oily product. The aqueous layer is separated the remaining organic layer is further extracted with water The resulting oily product is extracted with ethyl acetate the extract is dried concentrated under reduced pressure