methylidenecyclopentane

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

Procedure: To a solution of methyl 4-(allyloxy)benzoate 26.1 (3.00 g, 16.0 mmol) and methylenecyclopentane (1.9 g, 23.0 mmol) (commercially available from Sigma-Aldrich, St. Louis, Mo., USA) in DCM (5.0 mL) was added Hoveyda-Grubbs reagent (0.39 g, 0.62 mmol), (commercially available from Sigma-Aldrich, St. Louis, Mo., USA) at room temperature. The resulting reaction mixture was degassed three times and then stirred at 55° C. under nitrogen overnight. The reaction mixture was purified by CombiFlash® silica gel column chromatography (hexane/EtOAc 95/5) to give 26.2, (2.60 g, yield 68%). 1H NMR (500 MHz, CDCl3) δ ppm 7.82-7.93 (2H, m), 6.80-6.88 (2H, m), 5.44-5.56 (1H, m), 4.47 (2H, d, J=6.6 Hz), 3.80 (3H, s), 2.20-2.31 (4H, m), 1.50-1.71 (4H, m). at room temperature The resulting reaction mixture was degassed three times The reaction mixture was purified by CombiFlash® silica gel column chromatography (hexane/EtOAc 95/5)

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

Conditions: temp:-30.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of an (R)-binaphthol-dibromotitanium complex which had been prepared in the same manner as in Example 6 was cooled to -30° C. and added with 82 mg (1 mmole) of methylenecyclopentane (manufactured by Aldrich Corp.) and 88 mg (1 mmole) of methyl glyoxylate, followed by reaction for 3 hours. Then, 10 ml of an aqueous sodium hydrogen-carbonate solution was added to terminate the reaction. The reaction mixture was filtered through Celite and extracted with two 20 ml portions of diethyl ether and two 20 ml portions of ethyl acetate, and the extract was dried over anhydrous magnesium sulfate. Thereafter, the solvents were distilled off, and hexane was added to the residue to crystallize binaphthol. The remaining solution was purified by means of silica gel column chromatography to obtain 156 mg of methyl (R)-2-hydroxy-3-(l-cyclopentenyl)propionate. The yield was 92%. A solution of an (R)-binaphthol-dibromotitanium complex which had been prepared in the same manner as in Example 6 followed by reaction for 3 hours to terminate the reaction The reaction mixture was filtered through Celite extracted with two 20 ml portions of diethyl ether and two 20 ml portions of ethyl acetate the extract was dried over anhydrous magnesium sulfate Thereafter, the solvents were distilled off hexane was added to the residue to crystallize binaphthol The remaining solution was purified by means of silica gel column chromatography

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

Procedure: Under similar reaction conditions as in Example 5, methylenecyclohexane, methylenecyclopentane, 2-methyl-1-pentene, 2,4,4-trimethyl-2-pentene and 2,3-diphenyl-1-propene underwent the isomerization to the thermodynamically more stable isomers shown in Table 1. The isomerization of 2-methyl-1-pentene afforded only 2-methyl-2-pentene and 4-methyl-2-pentenes were not observed.

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

Procedure: Under similar reaction conditions as in Example 5, methylenecyclohexane, methylenecyclopentane, 2-methyl-1-pentene, 2,4,4-trimethyl-2-pentene and 2,3-diphenyl-1-propene underwent the isomerization to the thermodynamically more stable isomers shown in Table 1. The isomerization of 2-methyl-1-pentene afforded only 2-methyl-2-pentene and 4-methyl-2-pentenes were not observed.

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

Procedure: To a solution of methylenecyclopentane (246 mg, 3 mmol) in THF (7.5 mL) is added 9-BBN (7.5 mL, 0.5M in THF, 3 mmol) and the mixture is stirred at RT for 18 h. A mixture of 5-(2-benzyloxy-4-iodophenyl)-1,1-dioxo-1,2,5-thiadiazolidin-3-one (200 mg, 0.45 mmol), 3.38 mL of the borane solution previously prepared (0.675 mmol), resin-bound PPh3Pd (100 mg) and Na2CO3 (0.9 mL, 2M) in DME (5 mL) is heated in a microwave apparatus at 110° C. for 15 min. The mixture is filtered and the solvent removed under reduced pressure to give the title compound which is used directly in the next step. is heated in a microwave apparatus at 110° C. for 15 min The mixture is filtered the solvent removed under reduced pressure

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

Procedure: N-CBZ-L-serine methyl ester (3.15 g) was dissolved in 40 ml of dichloromethane at 0° C. under argon. Methylenecyclopentane (20 ml) was added, followed by 16 drops of concentrated sulfuric acid. The contents of the vessel were stirred at room temperature overnight then poured into dilute aqueous sodium hydrogen carbonate and extracted with chlorofrom (2×30 ml). The organic layer was dried over sodium sulfate and evaporated. The residual oil was chromatographed on silica gel with 50/50 petroleum ether/diethyl ether to give an oil (78% yield). The product, N-CBZ-O-(1-methylycyclopentyl)-L-serine methyl ester, was confirmed by NMR spectroscopy. extracted with chlorofrom (2×30 ml) The organic layer was dried over sodium sulfate evaporated The residual oil was chromatographed on silica gel with 50/50 petroleum ether/diethyl ether

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

Procedure: N-CBZ-L-serine methyl ester (3.15 g) was dissolved in 40 ml of dichloromethane at 0° C. under argon. Methylenecyclopentane (20 ml) was added, followed by 16 drops of concentrated sulfuric acid. The contents of the vessel were stirred at room temperature overnight then poured into dilute aqueous sodium hydrogen carbonate and extracted with chlorofrom (2×30 ml). The organic layer was dried over sodium sulfate and evaporated. The residual oil was chromatographed on silica gel with 50/50 petroleum ether/diethyl ether to give an oil (78% yield). The product, N-CBZ-O-(1-methylycyclopentyl)-L-serine methyl ester, was confirmed by NMR spectroscopy. extracted with chlorofrom (2×30 ml) The organic layer was dried over sodium sulfate evaporated The residual oil was chromatographed on silica gel with 50/50 petroleum ether/diethyl ether

Conditions: temp:55.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of methyl 4-(allyloxy)benzoate 26.1 (3.00 g, 16.0 mmol) and methylenecyclopentane (1.9 g, 23.0 mmol) (commercially available from Sigma-Aldrich, St. Louis, Mo., USA) in DCM (5.0 mL) was added Hoveyda-Grubbs reagent (0.39 g, 0.62 mmol), (commercially available from Sigma-Aldrich, St. Louis, Mo., USA) at room temperature. The resulting reaction mixture was degassed three times and then stirred at 55° C. under nitrogen overnight. The reaction mixture was purified by CombiFlash® silica gel column chromatography (hexane/EtOAc 95/5) to give 26.2, (2.60 g, yield 68%). 1H NMR (500 MHz, CDCl3) δ ppm 7.82-7.93 (2H, m), 6.80-6.88 (2H, m), 5.44-5.56 (1H, m), 4.47 (2H, d, J=6.6 Hz), 3.80 (3H, s), 2.20-2.31 (4H, m), 1.50-1.71 (4H, m). at room temperature The resulting reaction mixture was degassed three times The reaction mixture was purified by CombiFlash® silica gel column chromatography (hexane/EtOAc 95/5)