benzyl cyclopent-3-ene-1-carboxylate

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

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of (−)-α-pinene (5.80 g, 42.6 mmol) in THF (10 mL) was cooled to 0° C. and a solution of borane-Me2S (10N, 1.5 mL, 15 mmol) was added. The mixture was stirred for 4 h at 0° C. and benzyl cyclopent-3-enecarboxylate (3.5 g, 17 mmol) was added. The reaction mixture was allowed to warm to ambient temperature and stirred overnight. The mixture was cooled to 0° C. again and quenched with water (2 mL) and aqueous NaOH (3N, 15 mL). Then 30% hydrogen peroxide (20 mL) was added dropwise. The mixture was stirred for 1 h at 0° C. and diluted with water (20 mL) and EtOAc (50 mL). The two layers were separated and the aqueous phase was extracted with EtOAc (50 mL×3). The combined organic phases were washed with brine (200 mL×3), dried over anhydrous sodium sulfate, and concentrated. The residue was purified by flash column chromatography on silica gel (EtOAc/hexane=1:4) to afford benzyl 3-hydroxycyclopentanecarboxylate (1.4 g, 37% yield). to warm to ambient temperature stirred overnight The mixture was cooled to 0° C. again quenched with water (2 mL) and aqueous NaOH (3N, 15 mL) Then 30% hydrogen peroxide (20 mL) was added dropwise The mixture was stirred for 1 h at 0° C. diluted with water (20 mL) and EtOAc (50 mL) The two layers were separated the aqueous phase was extracted with EtOAc (50 mL×3) The combined organic phases were washed with brine (200 mL×3) dried over anhydrous sodium sulfate concentrated The residue was purified by flash column chromatography on silica gel (EtOAc/hexane=1:4)

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

Procedure: K2CO3 (35.0 g, 255 mmol) was added to a solution of cyclopent-3-enecarboxylic acid (20.0 g, 178 mmol) in acetonitrile (500 mL) followed by addition of benzyl bromide (36.6 g, 214 mmol). The reaction mixture was stirred for 12 h at ambient temperature. The mixture was filtered and washed with acetonitrile (200 mL). The filtrate and washings were combined and concentrated to dryness. The residue was purified by flash column chromatography on silica gel (hexane/EtOAc=10:1) to afford benzyl cyclopent-3-enecarboxylate (26.5 g, 74% yield) as an oil. The mixture was filtered washed with acetonitrile (200 mL) concentrated to dryness The residue was purified by flash column chromatography on silica gel (hexane/EtOAc=10:1)

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

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of (−)-α-pinene (5.80 g, 42.6 mmol) in THF (10 mL) was cooled to 0° C. and a solution of borane-Me2S (10N, 1.5 mL, 15 mmol) was added. The mixture was stirred for 4 h at 0° C. and benzyl cyclopent-3-enecarboxylate (3.5 g, 17 mmol) was added. The reaction mixture was allowed to warm to ambient temperature and stirred overnight. The mixture was cooled to 0° C. again and quenched with water (2 mL) and aqueous NaOH (3N, 15 mL). Then 30% hydrogen peroxide (20 mL) was added dropwise. The mixture was stirred for 1 h at 0° C. and diluted with water (20 mL) and EtOAc (50 mL). The two layers were separated and the aqueous phase was extracted with EtOAc (50 mL×3). The combined organic phases were washed with brine (200 mL×3), dried over anhydrous sodium sulfate, and concentrated. The residue was purified by flash column chromatography on silica gel (EtOAc/hexane=1:4) to afford benzyl 3-hydroxycyclopentanecarboxylate (1.4 g, 37% yield). to warm to ambient temperature stirred overnight The mixture was cooled to 0° C. again quenched with water (2 mL) and aqueous NaOH (3N, 15 mL) Then 30% hydrogen peroxide (20 mL) was added dropwise The mixture was stirred for 1 h at 0° C. diluted with water (20 mL) and EtOAc (50 mL) The two layers were separated the aqueous phase was extracted with EtOAc (50 mL×3) The combined organic phases were washed with brine (200 mL×3) dried over anhydrous sodium sulfate concentrated The residue was purified by flash column chromatography on silica gel (EtOAc/hexane=1:4)

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

Procedure: K2CO3 (35.0 g, 255 mmol) was added to a solution of cyclopent-3-enecarboxylic acid (20.0 g, 178 mmol) in acetonitrile (500 mL) followed by addition of benzyl bromide (36.6 g, 214 mmol). The reaction mixture was stirred for 12 h at ambient temperature. The mixture was filtered and washed with acetonitrile (200 mL). The filtrate and washings were combined and concentrated to dryness. The residue was purified by flash column chromatography on silica gel (hexane/EtOAc=10:1) to afford benzyl cyclopent-3-enecarboxylate (26.5 g, 74% yield) as an oil. The mixture was filtered washed with acetonitrile (200 mL) concentrated to dryness The residue was purified by flash column chromatography on silica gel (hexane/EtOAc=10:1)

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The benzyl cyclopent-3-ene-1-carboxylate (2.0 g, 9.89 mmol) was dissolved in 20 mL of THF and cooled to 0° C. under nitrogen. Borane-THF complex (0.95 mL, 9.89 mmol) was added via syringe and the mixture was stirred for 30 minutes at 0° C. Sodium perborate tetrahydrate solution (100 mL of 0.33 M aqueous solution) was added, and after 30 minutes the reaction mixture was extracted with ethyl acetate. The combined extracts were washed with water and brine and then dried over sodium sulfate. Filtration and concentration provided the crude product which was purified by chromatography on silica gel eluting with 10 to 30% EtOAc in hexanes to provide benzyl 3-hydroxycyclopentanecarboxylate. Borane-THF complex (0.95 mL, 9.89 mmol) was added via syringe after 30 minutes the reaction mixture was extracted with ethyl acetate The combined extracts were washed with water and brine dried over sodium sulfate Filtration and concentration provided the crude product which was purified by chromatography on silica gel eluting with 10 to 30% EtOAc in hexanes

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

Procedure: To a solution of cyclopent-3-ene-1-carboxylic acid (9.63 g, 85.88 mmol) in 143 mL of degassed DMF was added potassium carbonate (14.24 g, 103.06 mmol) and benzyl bromide (11.24 mL, 94.47 mmol). The mixture was stirred for 2 hours at ambient temperature, and then poured into 150 mL of water and extracted with ethyl acetate. The extracts were washed with water and brine, and dried over sodium sulfate. Filtration and concentration under vacuum afforded benzyl cyclopent-3-ene-1-carboxylate as an oil. extracted with ethyl acetate The extracts were washed with water and brine dried over sodium sulfate Filtration and concentration under vacuum

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of (−)-α-pinene (5.80 g, 42.6 mmol) in THF (10 mL) was cooled to 0° C. and a solution of borane-Me2S (10N, 1.5 mL, 15 mmol) was added. The mixture was stirred for 4 h at 0° C. and benzyl cyclopent-3-enecarboxylate (3.5 g, 17 mmol) was added. The reaction mixture was allowed to warm to ambient temperature and stirred overnight. The mixture was cooled to 0° C. again and quenched with water (2 mL) and aqueous NaOH (3N, 15 mL). Then 30% hydrogen peroxide (20 mL) was added dropwise. The mixture was stirred for 1 h at 0° C. and diluted with water (20 mL) and EtOAc (50 mL). The two layers were separated and the aqueous phase was extracted with EtOAc (50 mL×3). The combined organic phases were washed with brine (200 mL×3), dried over anhydrous sodium sulfate, and concentrated. The residue was purified by flash column chromatography on silica gel (EtOAc/hexane=1:4) to afford benzyl 3-hydroxycyclopentanecarboxylate (1.4 g, 37% yield). to warm to ambient temperature stirred overnight The mixture was cooled to 0° C. again quenched with water (2 mL) and aqueous NaOH (3N, 15 mL) Then 30% hydrogen peroxide (20 mL) was added dropwise The mixture was stirred for 1 h at 0° C. diluted with water (20 mL) and EtOAc (50 mL) The two layers were separated the aqueous phase was extracted with EtOAc (50 mL×3) The combined organic phases were washed with brine (200 mL×3) dried over anhydrous sodium sulfate concentrated The residue was purified by flash column chromatography on silica gel (EtOAc/hexane=1:4)

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

Procedure: K2CO3 (35.0 g, 255 mmol) was added to a solution of cyclopent-3-enecarboxylic acid (20.0 g, 178 mmol) in acetonitrile (500 mL) followed by addition of benzyl bromide (36.6 g, 214 mmol). The reaction mixture was stirred for 12 h at ambient temperature. The mixture was filtered and washed with acetonitrile (200 mL). The filtrate and washings were combined and concentrated to dryness. The residue was purified by flash column chromatography on silica gel (hexane/EtOAc=10:1) to afford benzyl cyclopent-3-enecarboxylate (26.5 g, 74% yield) as an oil. The mixture was filtered washed with acetonitrile (200 mL) concentrated to dryness The residue was purified by flash column chromatography on silica gel (hexane/EtOAc=10:1)