3-methyloxolane-2-carboxylic acid

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: (2RS,3SR)-3-Methyl-2-tetrahydrofuroic acid 91.3g) was converted to the acid chloride with oxalyl chloride (2.54g, 1.75mls) in dichloromethane (20mls) as described in Example 1(a) . Diazomethane was passed through a solution of the acid chloride in dichloromethane (20mls), cooled in ice/water until i.r. analysis showed no starting material. Hydrobromic acid (2mls, 49% w/v aqueous solution), was added dropwise and the reaction mixture stirred vigorously for 10min. T.l.c. analysis showed complete conversion to the title compound. The solution was washed with water, brine and dried. The solvent was washed with water, brine and dried. The solvent was evaporated and the residue flash chromatographed on silica gel, eluting with 5 and then 10% ethyl acetate/hexane to give the product as an almost colourless oil, (1.621g, 79%); vmax (CH2Cl2) 1732cm-1 ; δH (CDCl3) 0.96 (3H, d, J 7.2Hz), 1.70 (1H, m), 2.17 (1H, m), 2.70 (1H, m), 3.93 (1H, m), 4.12 and 4.25 (2H, ABq, J 14.7Hz) and 4.49 (1H, d, J 7.3Hz). [Mass spectrum: +ve ion (ammonia) MNH4 (224)].

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: 3-Methyl-2-furoic acid (5g) in ethyl acetate (100ml) and 5% rhodium on charcoal catalyst (0.5g) were hydrogenated at ambient temperature and the atmosphere for 6-7h. The catalyst was filtered off and replaced with a further quantity (lg) of catalyst. The reaction mixture was hydrogenated for a further 7h. This procedure was repeated again until no more hydrogen was absorbed. After filtration through kieselguhr and removal of solvent under reduced pressure, the title compound was obtained as a colourless oil (5.096g, quant.); vmax (CH2Cl2) 3674, 3377(br), 1770 and 1722cm-1 ; δH (CHCl3) 1.08 (3H, d, J 7.1Hz), 1.72 (1H, m), 2.16 (1H, m), 2.68 (1H, m), 3.94 (1H, m), 4.18 (1H, m), 4.47 (1H, d, J 7.5Hz) and 9.42 (1H, v. br s, exch). [Mass spectrum: +ve ion (ammonia) MNH4+ (148)]. were hydrogenated at ambient temperature The catalyst was filtered off The reaction mixture was hydrogenated for a further 7h was absorbed After filtration through kieselguhr and removal of solvent under reduced pressure

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: (2RS,3SR)-3-Methyl-2-tetrahydrofuroic acid 91.3 g) was converted to the acid chloride with oxalyl chloride (2.54 g, 1.75 mls) in dichloromethane (20 mls) as described in Example 1 (a). Diazomethane was passed through a solution of the acid chloride in dichloromethane (20 mls), cooled in ice/water until i.r. analysis showed no starting material. Hydrobromic acid (2 mls, 49% w/v aqueous solution), was added dropwise and the reaction mixture stirred vigorously for 10 min. T.l.c. analysis showed complete conversion to the title compound. The solution was washed with water, brine and dried. The solvent was washed with water, brine and dried. The solvent was evaporated and the residue flash chromatographed on silica gel, eluting with 5 and then 10% ethyl acetate/hexane to give the product as an almost colourless oil, (1.621 g, 79%); νmax (CH2Cl2) 1732 cm-1 ; δH (CDCl3) 0.96 (3 H, d, J 7.2 Hz), 1.70 (1 H, m), 2.17 (1 H, m), 2.70 (1 H, m), 3.93 (1 H, m), 4.12 and 4.25 (2 H, ABq, J 14.7 Hz) and 4.49 (1 H, d, J 7.3 Hz). [Mass spectrum: +ve ion (ammonia) MNH4 (224)].

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: (2RS,3SR)-3-Methyl-2-tetrahydrofuroic acid 91.3 g) was converted to the acid chloride with oxalyl chloride (2.54 g, 1.75 mls) in dichloromethane (20 mls) as described in Example 1 (a). Diazomethane was passed through a solution of the acid chloride in dichloromethane (20 mls), cooled in ice/water until i.r. analysis showed no starting material. Hydrobromic acid (2 mls, 49% w/v aqueous solution), was added dropwise and the reaction mixture stirred vigorously for 10 min. T.l.c. analysis showed complete conversion to the title compound. The solution was washed with water, brine and dried. The solvent was washed with water, brine and dried. The solvent was evaporated and the residue flash chromatographed on silica gel, eluting with 5 and then 10% ethyl acetate/hexane to give the product as an almost colourless oil, (1.621 g, 79%); νmax (CH2Cl2) 1732 cm-1 ; δH (CDCl3) 0.96 (3 H, d, J 7.2 Hz), 1.70 (1 H, m), 2.17 (1 H, m), 2.70 (1 H, m), 3.93 (1 H, m), 4.12 and 4.25 (2 H, ABq, J 14.7 Hz) and 4.49 (1 H, d, J 7.3 Hz). [Mass spectrum: +ve ion (ammonia) MNH4 (224)].

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: 3-Methyl-2-furoic acid (5 g) in ethyl acetate (100 ml) and 5% rhodium on charcoal catalyst (0.5 g) were hydrogenated at ambient temperature and the atmosphere for 6-7 h. The catalyst was filtered off and replaced with a further quantity (1 g) of catalyst. The reaction mixture was hydrogenated for a further 7 h. This procedure was repeated again until no more hydrogen was absorbed. After filtration through kieselguhr and removal of solvent under reduced pressure, the title compound was obtained as a colourless oil (5.096 g, quant.); νmax (CH2Cl2) 3674, 3377(br), 1770 and 1722 cm-1 ; δH (CHC13) 1.08 (3 H, d, J 7.1 Hz), 1.72 (1 H, m), 2.16 (1 H, m), 2.68 (1 H, m), 3.94 (1 H, m), 4.18 (1 H, m), 4.47 (1 H, d, J 7.5 Hz) and 9.42 (1 H, v. br s, exch). [Mass spectrum: +ve ion (ammonia) MNH4+ (148)]. were hydrogenated at ambient temperature The catalyst was filtered off The reaction mixture was hydrogenated for a further 7 h was absorbed After filtration through kieselguhr and removal of solvent under reduced pressure

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: (2RS,3SR)-3-Methyl-2-tetrahydrofuroic acid 91.3g) was converted to the acid chloride with oxalyl chloride (2.54g, 1.75mls) in dichloromethane (20mls) as described in Example 1(a) . Diazomethane was passed through a solution of the acid chloride in dichloromethane (20mls), cooled in ice/water until i.r. analysis showed no starting material. Hydrobromic acid (2mls, 49% w/v aqueous solution), was added dropwise and the reaction mixture stirred vigorously for 10min. T.l.c. analysis showed complete conversion to the title compound. The solution was washed with water, brine and dried. The solvent was washed with water, brine and dried. The solvent was evaporated and the residue flash chromatographed on silica gel, eluting with 5 and then 10% ethyl acetate/hexane to give the product as an almost colourless oil, (1.621g, 79%); vmax (CH2Cl2) 1732cm-1 ; δH (CDCl3) 0.96 (3H, d, J 7.2Hz), 1.70 (1H, m), 2.17 (1H, m), 2.70 (1H, m), 3.93 (1H, m), 4.12 and 4.25 (2H, ABq, J 14.7Hz) and 4.49 (1H, d, J 7.3Hz). [Mass spectrum: +ve ion (ammonia) MNH4 (224)].

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: 3-Methyl-2-furoic acid (5g) in ethyl acetate (100ml) and 5% rhodium on charcoal catalyst (0.5g) were hydrogenated at ambient temperature and the atmosphere for 6-7h. The catalyst was filtered off and replaced with a further quantity (lg) of catalyst. The reaction mixture was hydrogenated for a further 7h. This procedure was repeated again until no more hydrogen was absorbed. After filtration through kieselguhr and removal of solvent under reduced pressure, the title compound was obtained as a colourless oil (5.096g, quant.); vmax (CH2Cl2) 3674, 3377(br), 1770 and 1722cm-1 ; δH (CHCl3) 1.08 (3H, d, J 7.1Hz), 1.72 (1H, m), 2.16 (1H, m), 2.68 (1H, m), 3.94 (1H, m), 4.18 (1H, m), 4.47 (1H, d, J 7.5Hz) and 9.42 (1H, v. br s, exch). [Mass spectrum: +ve ion (ammonia) MNH4+ (148)]. were hydrogenated at ambient temperature The catalyst was filtered off The reaction mixture was hydrogenated for a further 7h was absorbed After filtration through kieselguhr and removal of solvent under reduced pressure

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: (2RS,3SR)-3-Methyl-2-tetrahydrofuroic acid 91.3 g) was converted to the acid chloride with oxalyl chloride (2.54 g, 1.75 mls) in dichloromethane (20 mls) as described in Example 1(a). Diazomethane was passed through a solution of the acid chloride in dichloromethane (20 mls), cooled in ice/water until i.r. analysis showed no starting material. Hydrobromic acid (2 mls, 49% w/v aqueous solution), was added dropwise and the reaction mixture stirred vigorously for 10 min. T.l.c. analysis showed complete conversion to the title compound. The solution was washed with water, brine and dried. The solvent was washed with water, brine and dried. The solvent was evaporated and the residue flash chromatographed on silica gel, eluting with 5 and then 10% ethyl acetate/hexane to give the product as an almost colourless oil, (1.621 g, 79%); νmax (CH2Cl2) 1732 cm-1 ; δH (CDCl3) 0.96 (3H, d, 7.2 Hz), 1.70 (1H, m), 2.17 (1H, m), 2.70 (1H, m), 3.93 (1H, m), 4.12 and 4.25 (2H, ABq, J 14.7 Hz) and 4.49 (1H, d, J 7.3 Hz). [Mass spectrum: +ve ion (ammonia) MNH4 (224)].

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: 3-Methyl-2-furoic acid (5 g) in ethyl acetate (100 ml) and 5% rhodium on charcoal catalyst (0.5 g) were hydrogenated at ambient temperature and the atmosphere for 6-7 h. The catalyst was filtered off and replaced with a further quantity (1 g) of catalyst. The reaction mixture was hydrogenated for a further 7 h. This procedure was repeated is again until no more hydrogen was absorbed. After filtration through kieselguhr and removal of solvent under reduced pressure, the title compound was obtained as a colourless oil (5.096 g, quant.); νmax (CH2Cl2) 3674, 3377(br), 1770 and 1722 cm-1 ; δH (CHCl3) 1.08 (3H, d, J 7.1 Hz), 1.72 (1H, m), 2.16 (1H, m), 2.68 (1H, m), 3.94 (1H, m), 4.18 (1H, m), 4.47 (1H, d, J 7.5 Hz) and 9.42 (1H, v. br s, exch). [Mass spectrum: +ve ion (ammonia) MNH4+ (148)]. were hydrogenated at ambient temperature The catalyst was filtered off The reaction mixture was hydrogenated for a further 7 h was absorbed After filtration through kieselguhr and removal of solvent under reduced pressure

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: (2RS,3SR)-3-Methyl-2-tetrahydrofuroic acid 91.3 g) was converted to the acid chloride with oxalyl chloride (2.54 g, 1.75 mls) in dichloromethane (20 mls) as described in Example 1 (a). Diazomethane was passed through a solution of the acid chloride in dichloromethane (20 mls), cooled in ice/water until i.r. analysis showed no starting material. Hydrobromic acid (2 mls, 49% w/v aqueous solution), was added dropwise and the reaction mixture stirred vigorously for 10 min. T.l.c. analysis showed complete conversion to the title compound. The solution was washed with water, brine and dried. The solvent was washed with water, brine and dried. The solvent was evaporated and the residue flash chromatographed on silica gel, eluting with 5 and then 10% ethyl acetate/hexane to give the product as an almost colourless oil, (1.621 g, 79%); νmax (CH2Cl2) 1732 cm-1 ; δH (CDCl3) 0.96 (3 H, d, J 7.2 Hz), 1.70 (1 H, m), 2.17 (1 H, m), 2.70 (1 H, m), 3.93 (1 H, m), 4.12 and 4.25 (2 H, ABq, J 14.7 Hz) and 4.49 (1 H, d, J 7.3 Hz). [Mass spectrum: +ve ion (ammonia) MNH4 (224)].

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: 3-Methyl-2-furoic acid (5 g) in ethyl acetate (100 ml) and 5% rhodium on charcoal catalyst (0.5 g) were hydrogenated at ambient temperature and the atmosphere for 6-7 h. The catalyst was filtered off and replaced with a further quantity (1 g) of catalyst. The reaction mixture was hydrogenated for a further 7 h. This procedure was repeated again until no more hydrogen was absorbed. After filtration through kieselguhr and removal of solvent under reduced pressure, the title compound was obtained as a colourless oil (5.096 g, quant.); νmax (CH2Cl2) 3674, 3377(br), 1770 and 1722 cm-1 ; δH (CHC13) 1.08 (3 H, d, J 7.1 Hz), 1.72 (1 H, m), 2.16 (1 H, m), 2.68 (1 H, m), 3.94 (1 H, m), 4.18 (1 H, m), 4.47 (1 H, d, J 7.5 Hz) and 9.42 (1 H, v. br s, exch). [Mass spectrum: +ve ion (ammonia) MNH4+ (148)]. were hydrogenated at ambient temperature The catalyst was filtered off The reaction mixture was hydrogenated for a further 7 h was absorbed After filtration through kieselguhr and removal of solvent under reduced pressure

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: (2RS,3SR)-3-Methyl-2-tetrahydrofuroic acid 91.3g) was converted to the acid chloride with oxalyl chloride (2.54g, 1.75mls) in dichloromethane (20mls) as described in Example 1(a) . Diazomethane was passed through a solution of the acid chloride in dichloromethane (20mls), cooled in ice/water until i.r. analysis showed no starting material. Hydrobromic acid (2mls, 49% w/v aqueous solution), was added dropwise and the reaction mixture stirred vigorously for 10min. T.l.c. analysis showed complete conversion to the title compound. The solution was washed with water, brine and dried. The solvent was washed with water, brine and dried. The solvent was evaporated and the residue flash chromatographed on silica gel, eluting with 5 and then 10% ethyl acetate/hexane to give the product as an almost colourless oil, (1.621g, 79%); vmax (CH2Cl2) 1732cm-1 ; δH (CDCl3) 0.96 (3H, d, J 7.2Hz), 1.70 (1H, m), 2.17 (1H, m), 2.70 (1H, m), 3.93 (1H, m), 4.12 and 4.25 (2H, ABq, J 14.7Hz) and 4.49 (1H, d, J 7.3Hz). [Mass spectrum: +ve ion (ammonia) MNH4 (224)].