methyl 5-hydroxypentanoate

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: A solution of tert-butylchlorodimethylsilane (27.1 g, 179.79 mmol) in DCM (50 mL) was added dropwise to a stirred solution of methyl 5-hydroxypentanoate (CAS no. 14273-92-8, Huckstep, M.; Taylor, R. J. K.; Caton, M. P. L. Synthesis 1982, 10, 881) (19.8 g, 149.82 mmol) and 1H-imidazole (15.30 g, 224.73 mmol) in DCM (200 mL) at 5° C., over a period of 10 minutes under nitrogen. The resulting suspension was stirred at ambient temperature for 6 hours. The reaction mixture was diluted with DCM (250 mL), and washed sequentially with water (2×200 mL) and saturated brine (200 mL). The organic layer was dried (MgSO4) and evaporated. The residue was purified by flash silica chromatography, eluting with 10 to 50% ethyl acetate in isohexane to afford the product (19.3 g, 52%). washed sequentially with water (2×200 mL) and saturated brine (200 mL) The organic layer was dried (MgSO4) evaporated The residue was purified by flash silica chromatography eluting with 10 to 50% ethyl acetate in isohexane

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

Procedure: reaction of valerolactone with methyl alcohol in the presence of sulphuric acid to produce methyl 5-hydroxypentanoate;

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

Procedure: reaction of valerolactone with methyl alcohol in the presence of sulphuric acid to produce methyl 5-hydroxypentanoate;

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

Procedure: reaction of valerolactone with methyl alcohol in the presence of sulphuric acid to produce methyl 5-hydroxypentanoate,

Conditions: temp:50.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of sodium methoxide (71.3 mg, 1.32 mmol) in anhydrous MeOH (4 ml), tetrahydro-pyran-2-one (1.32 g, 13.2 mmol) is added dropwise at room temperature under nitrogen. The mixture is stirred at 50° C. for 4 hours and filtered through a silica gel short column (eluent: diethyl ether). Collected filtrate is concentrated under reduced pressure to give 5-hydroxy-pentanoic acid methyl ester; 1H NMR (400 MHz, chloroform-d) ppm 1.57-1.76 (m, 4H), 2.35 (m, 2H), 3.65 (m, 5H). filtered through a silica gel short column (eluent: diethyl ether) Collected filtrate is concentrated under reduced pressure

Conditions: temp:-20.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To prepare 2, freshly distilled δ-valerolactone (1) (856 mg) in methanol (17 ml) was treated with concentrated H2SO4 (100 μl) and refluxed for 12 hours. The solution was cooled to −20° C., treated with NaHCO3 (80 mg), and stirred for 10 minutes. The reaction mixture was filtered and the solvent was removed in vacuum. The residue was taken up in DCM (10 ml), dried over Na2SO4, filtered, and concentrated in vacuum to give methyl 5-hydroxypentanoate (2) (Huckstep et al., Synthesis 10:881-82 (1982), which is hereby incorporated by reference in its entirety) (1071 mg, 94%) as a colorless oil, which was used directly without any further purification. 1H NMR (400 MHz, acetone-d6): δ 1.55 (2H, m), 1.68 (2H, m), 2.35 (2H, t, J=7.4 Hz), 3.57 (2H, m), 3.64 (3H, s); 13C NMR (100 MHz, acetone-d6): δ 22.2, 32.9, 34.1, 51.5, 61.9, 174.2. See FIGS. 75A-B. refluxed for 12 hours The reaction mixture was filtered the solvent was removed in vacuum dried over Na2SO4 filtered concentrated in vacuum

Conditions: temp:50.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of sodium methoxide (71.3 mg, 1.32 mmol) in anhydrous MeOH (4 ml), tetrahydro-pyran-2-one (1.32 g, 13.2 mmol) is added dropwise at room temperature under nitrogen. The mixture is stirred at 50° C. for 4 hours and filtered through a silica gel short column (eluent: diethyl ether). Collected filtrate is concentrated under reduced pressure to give 5-hydroxy-pentanoic acid methyl ester; 1H NMR (400 MHz, chloroform-d) ppm 1.57-1.76 (m, 4H), 2.35 (m, 2H), 3.65 (m, 5H). filtered through a silica gel short column (eluent: diethyl ether) Collected filtrate is concentrated under reduced pressure

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

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

Conditions: temp:-20.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To prepare 2, freshly distilled δ-valerolactone (1) (856 mg) in methanol (17 ml) was treated with concentrated H2SO4 (100 μl) and refluxed for 12 hours. The solution was cooled to −20° C., treated with NaHCO3 (80 mg), and stirred for 10 minutes. The reaction mixture was filtered and the solvent was removed in vacuum. The residue was taken up in DCM (10 ml), dried over Na2SO4, filtered, and concentrated in vacuum to give methyl 5-hydroxypentanoate (2) (Huckstep et al., Synthesis 10:881-82 (1982), which is hereby incorporated by reference in its entirety) (1071 mg, 94%) as a colorless oil, which was used directly without any further purification. 1H NMR (400 MHz, acetone-d6): δ 1.55 (2H, m), 1.68 (2H, m), 2.35 (2H, t, J=7.4 Hz), 3.57 (2H, m), 3.64 (3H, s); 13C NMR (100 MHz, acetone-d6): δ 22.2, 32.9, 34.1, 51.5, 61.9, 174.2. See FIGS. 75A-B. refluxed for 12 hours The reaction mixture was filtered the solvent was removed in vacuum dried over Na2SO4 filtered concentrated in vacuum