3,3-dimethylhexanoic acid

反应条件: temp:0.00; pressure:0.00; stir:

反应条件: temp:0.00; pressure:0.00; stir:

反应条件: temp:0.00; pressure:0.00; stir:

反应条件: temp:0.00; pressure:0.00; stir:

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: Under N2, 1,1′-Carbonyldiimidazole (294 g, 1.82 mol) and THF (1000 mL) was slowly added to 3,3-dimethylhexanoic acid (238 g, 1.65 mol in 200 mL of THF), to a 2 L 3-necked flask. After the addition was completed, the solution was stirred at ambient temperature for 3 hours. Ethyl malonate potassium salt (281 g, 1.65 mol), THF (1500 mL) and magnesium chloride (157 g, 1.65 mol) were added under N2 to a flask equipped with an over-head stirrer. The mixture was stirred at 50° C. for 3 hours. It was then cooled down to room temperature and above acid imidazolide solution was added. The resultant slurry was stirred for 18 hours. H3PO4 (30%, 1.5 L) was added and the mixture was stirred for 1 hour. The aqueous layer was separated and extracted with MTBE (3×700 mL). The combined organic layer was washed with K2CO3 (25%, 2×500 mL) and brine (1000 mL) and dried over magnesium sulfate (˜40 g). The drying reagent was filtered and solvent was removed to give 250 g of ethyl 5,5-dimethyl-3-oxo-octanoate (yield 71%). After the addition equipped with an over-head stirrer The mixture was stirred at 50° C. for 3 hours was added The resultant slurry was stirred for 18 hours the mixture was stirred for 1 hour The aqueous layer was separated extracted with MTBE (3×700 mL) The combined organic layer was washed with K2CO3 (25%, 2×500 mL) and brine (1000 mL) dried over magnesium sulfate (˜40 g) The drying reagent was filtered solvent was removed

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: Under N2, 1,1′-Carbonyldiimidazole (294 g, 1.82 mol) and THF (1000 mL) was slowly added to 3,3-dimethylhexanoic acid (238 g, 1.65 mol in 200 mL of THF), to a 2 L 3-necked flask. After the addition was completed, the solution was stirred at ambient temperature for 3 hours. Ethyl malonate potassium salt (281 g, 1.65 mol), THF (1500 mL) and magnesium chloride (157 g, 1.65 mol) were added under N2 to a flask equipped with an over-head stirrer. The mixture was stirred at 50° C. for 3 hours. It was then cooled down to room temperature and above acid imidazolide solution was added. The resultant slurry was stirred for 18 hours. H3PO4 (30%, 1.5 L) was added and the mixture was stirred for 1 hour. The aqueous layer was separated and extracted with MTBE (3×700 mL). The combined organic layer was washed with K2CO3 (25%, 2×500 mL) and brine (1000 mL) and dried over magnesium sulfate (˜40 g). The drying reagent was filtered and solvent was removed to give 250 g of ethyl 5,5-dimethyl-3-oxo-octanoate (yield 71%). After the addition equipped with an over-head stirrer The mixture was stirred at 50° C. for 3 hours was added The resultant slurry was stirred for 18 hours the mixture was stirred for 1 hour The aqueous layer was separated extracted with MTBE (3×700 mL) The combined organic layer was washed with K2CO3 (25%, 2×500 mL) and brine (1000 mL) dried over magnesium sulfate (˜40 g) The drying reagent was filtered solvent was removed

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: Ethyl 3,3-dimethylhexanoate (from above) (280 g, 1.63 mol), ethyl alcohol (400 mL) and aqueous sodium hydroxide solution (98 g, 2.45 mol, in 200 mL of water) were added to a 2-L round flask equipped with a stirring bar. The solution was then heated to refluxing temperature and stirred for 24 hours. After the reaction was finished, most of the solvents were removed by evaporation. The residue was taken up in 500 mL of ice water. It was then acidified to pH=3 with HCl (10%, w. ˜500 mL). The mixture was extracted with MTBE (3×500 mL). The combined MTBE extracts were washed with brine (2×50 mL) and dried over magnesium sulfate (˜40 g). The drying reagent was filtered and the MTBE was removed to give 223 g of 3,3-dimethylhexanoic acid (yield 95.1%). 1H NMR (CDCl3/300 MHz): δ2.25(s, 2H), 1.32-1.26(m, 4H), 1.02(s, 6H), 0.90(m, 3H) ppm; 13C NMR (CDCl3/300 MHz): δ179.0, 45.8, 44.6, 33.2, 27.2, 17.5, 14.8 ppm; MS 162 (M++NH4+). equipped with a stirring bar The solution was then heated to refluxing temperature were removed by evaporation The mixture was extracted with MTBE (3×500 mL) The combined MTBE extracts were washed with brine (2×50 mL) dried over magnesium sulfate (˜40 g) The drying reagent was filtered the MTBE was removed