2-pentylcyclopent-2-en-1-one

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: 750 ml of absolute methanol was introduced into a 2 liter flask. 17.3 g of sodium were added thereto. 580 g of methyl acetoacetate and 456 g of 2-pentyl-cyclopent-2-en-1-one were then added and the mixture was allowed to stand for 48 hours at the ambient temperature. The reaction product was neutralised with 45 g of acetic acid and then poured into 3 liters of a 10% aqueous sodium chloride solution. The product was then worked up as described in Example 1 (a). There were thus obtained 567 g (yield = 70%) of 2-n-pentyl-(1-carbomethoxy-2-oxopropyl)-1-cyclopentanone having: nD20 = 1.4702, d420 = 1.0545.

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

Procedure: The above prepared mixture (18 parts) was admixed with p-toluenesulfonic acid (0.9 part) and xylene (54 parts) and refluxed for 2 hours, during which by-produced water was eliminated by azeotropic distillation. The reaction mixture was treated as in Example 1 to give 2-n-pentyl-2-cyclopentenone in a yield of 96 %. The above prepared mixture (18 parts) refluxed for 2 hours, during which was eliminated by azeotropic distillation The reaction mixture was treated as in Example 1

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

Procedure: 3,4-dibromo-5-hydroxy-2(5H)-furanone (manufactured by SIGMA), Compound 3: 4-bromo-5-methoxy-5-(4-methoxyphenyl)-2(5H)-furanone (manufactured by SIGMA), and Compound 4: 4-{[3-bromo-2-(4-methoxyphenyl)-5-oxo-2,5-dihydro-2-furanyl]oxy}benzoate (manufactured by SIGMA) were used as test drugs. As positive controls, three (3) kinds of known compounds as an AI-2 inhibitory compounds, such as Compound 5: 4-hydroxy-2,5-dimethyl-3(2H)-furanone (manufactured by SIGMA), Compound 6: 2-methoxy-2,4-diphenyl-3(2H)-furanone (manufactured by SIGMA), and Compound 7: 2-pentyl-2-cyclopentene-1-one (manufactured by SIGMA) were used (see Bassseler et al., Bacteriol. 179, p. 4043-4045, 1997; Yoshida A. et al., Appl. Environ. Microbial., 71(5), p. 2372-2380, 2005; and Wen Z. T. et al., J. Bacteriol., 189(9), p. 2682-2691, 2004).

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

Procedure: A mixture of 184 mg (0.95 mM) of 1-ethynyl-1-pentyl-2-propenyl acetate and 13 mg (0.05 mM) of PdCl2 (CH3CN)2 in 1.2 ml of acetonitrile and 60 μl of glacial acetic acid was heated at 80° during 2 h. 1 Ml of methanol and some crystals of 4-dimethylaminopyridine were added to the reaction mixture and the whole was stirred for 45 minutes at room temperature, whereupon 10 ml of a 1:1 mixture of pentane/ether were added followed by a small quantity of potassium carbonate. The reaction mixture was then stirred for 30 minutes, it was then filtered and evaporated. The obtained residue gave by bulb to bulb distillation 104 mg of a colorless distillate constituted by the desired product having a purity of 92% (yield 66%). By carrying out the reaction in toluene instead of acetonitrile at a temperature of about 80°, the desired product was obtained, though in lower yields. was heated at 80° during 2 h were added it was then filtered evaporated The obtained residue gave by bulb to bulb distillation 104 mg of a colorless distillate

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

Procedure: A mixture of 184 mg (0.95 mM) of 1-ethynyl-1-pentyl-2-propenyl acetate and 13 mg (0.05 mM) of PdCl2 (CH3CN)2 in 1.2 ml of acetonitrile and 60 μl of glacial acetic acid was heated at 80° during 2 h. 1 Ml of methanol and some crystals of 4-dimethylaminopyridine were added to the reaction mixture and the whole was stirred for 45 minutes at room temperature, whereupon 10 ml of a 1:1 mixture of pentane/ether were added followed by a small quantity of potassium carbonate. The reaction mixture was then stirred for 30 minutes, it was then filtered and evaporated. The obtained residue gave by bulb to bulb distillation 104 mg of a colorless distillate constituted by the desired product having a purity of 92% (yield 66%). By carrying out the reaction in toluene instead of acetonitrile at a temperature of about 80°, the desired product was obtained, though in lower yields. was heated at 80° during 2 h were added it was then filtered evaporated The obtained residue gave by bulb to bulb distillation 104 mg of a colorless distillate

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

Procedure: A solution of 2-pentyl-2-cyclopenten-1-one (9.12 g, 60 mmole) in 140 ml of tetrahydrofurane (THF) was treated with an oxazaborolidine represented above, namely (S)-tetrahydro-1-methyl-3,3-diphenyl-1 H,3 H-pyrrolo[1,2-c][1,3,2] oxazaborole (16.7 ml; 0.36 M in toluene, 6.0 mmole; see D. J. Mathre, ref. cited). A solution of BH3.S(CH3)2 (3.30 ml=2.64 g, 34.8 mmole) in THF (60 ml) was added dropwise at 0° over 1 h. The reaction was stopped with 3 ml of methanol (development of H2), followed by ethyl ether and 5% HCl. The organic phase, which had been washed to neutrality (2x with water and 1x with brine), was separated and the solvent evaporated. 9.5 g of a crude product were obtained, which was distilled in a bulb-to-bulb apparatus (oven temp. 60°/11 Pa), to give 8.1 g of (+)-(1 R)-2-pentyl-2-cyclopenten-1-ol (yield 89%). The organic phase, which had been washed to neutrality (2x with water and 1x with brine) was separated the solvent evaporated 9.5 g of a crude product were obtained which was distilled in a bulb-to-bulb apparatus (oven temp. 60°/11 Pa)

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

Procedure: 750 ml of absolute methanol was introduced into a 2 liter flask. 17.3 g of sodium were added thereto. 580 g of methyl acetoacetate and 456 g of 2-pentyl-cyclopent-2-en-1-one were then added and the mixture was allowed to stand for 48 hours at the ambient temperature. The reaction product was neutralised with 45 g of acetic acid and then poured into 3 liters of a 10% aqueous sodium chloride solution. The product was then worked up as described in Example 1 (a). There were thus obtained 567 g (yield = 70%) of 2-n-pentyl-(1-carbomethoxy-2-oxopropyl)-1-cyclopentanone having: nD20 = 1.4702, d420 = 1.0545.

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

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