diethyl 2,2,12,12-tetramethyl-7-oxotridecanedioate

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: Under N2 atmosphere, to a solution of 2,2,12,12-tetramethyl-7-oxo-tridecanedioic acid diethyl ester (1.0 g, 2.70 mmol) and 1,3-propanedithiol (361 mg, 361 L, 3.24 mmol) in dichloromethane (20 mL; dried with Aluminum oxide, activated, neutral, Brockman I) was added boron trifluoride diethyl etherate (100 L) at rt. The reaction mixture was stirred for 3 h, diluted with dichloromethane (100 mL), and extracted with 5% NaOH solution (100 mL) and water (75 mL). The organic phase was dried over MgSO4, concentrated in vacuo, and dried in high vacuo to furnish 6-[2-(5-ethoxycarbonyl-5-methyl-hexyl)-[1,3]dithian-2-yl]-2,2-dimethyl-hexanoic acid ethyl ester (1.0 g, 80%) as a yellowish oil. 1H NMR (300 MHz, CDCl3/TMS): (ppm): 4.11 (q, 4H, J=7.1), 2.79 (t, 4H, J=5.6), 1.94 (m, 2 H), 1.84 (m, 4 H), 1.54 (m, 4 H), 1.39 (m, 4 H), 1.24 (t, 6H, J=7.1), 1.30-1.20 (m, 4 H), 1.16 (s, 12 H). 13C NMR (75 MHz, CDCl3/TMS): (ppm): 178.08, 60.33, 53.32, 42.27, 40.69, 38.28, 26.14, 25.67, 25.28, 24.71, 14.41. HRMS (LSIMS, nba): Calcd. for C24H45S2O4 (MH+): 461.2759, found 461.2774. extracted with 5% NaOH solution (100 mL) and water (75 mL) The organic phase was dried over MgSO4 concentrated in vacuo dried in high vacuo

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

Procedure: Under N2 atmosphere, to a solution of 2,2,12,12-tetramethyl-7-oxo-tridecanedioic acid diethyl ester (1.0 g, 2.70 mmol) and 1,3-propanedithiol (361 mg, 361 L, 3.24 mmol) in dichloromethane (20 mL; dried with Aluminum oxide, activated, neutral, Brockmann I) was added boron trifluoride diethyl etherate (100 L) at rt. The reaction mixture was stirred for 3 h, diluted with dichloromethane (100 mL), and extracted with 5% NaOH solution (100 mL) and water (75 mL). The organic phase was dried over MgSO4, concentrated in vacuo, and dried in high vacuo to furnish 6-[2-(5-ethoxycarbonyl-5-methyl-hexyl)-[1,3]dithian-2-yl]-2,2-dimethyl-hexanoic acid ethyl ester (1.0 g, 80%) as a yellowish oil. 1H NMR (300 MHz, CDCl3/TMS): (ppm): 4.11 (q, 4H, J=7.1), 2.79 (t, 4H, J=5.6), 1.94 (m, 2H), 1.84 (m, 4H), 1.54 (m, 4H), 1.39 (m, 4H), 1.24 (t, 6H, J=7.1), 1.30-1.20 (m, 4H), 1.16 (s, 12H). 13C NMR (75 MHz, CDCl3/TMS): (ppm): 178.08, 60.33, 53.32, 42.27, 40.69, 38.28, 26.14, 25.67, 25.28, 24.71, 14.41. HRMS (LSIMS, nba): Calcd. for C24H45S2O4 (MH+): 461.2759, found 461.2774. extracted with 5% NaOH solution (100 mL) and water (75 mL) The organic phase was dried over MgSO4 concentrated in vacuo dried in high vacuo

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

Procedure: Under N2 atmosphere, to a solution of 2,2,12,12-tetramethyl-7-oxo-tridecanedioic acid diethyl ester (1.0 g, 2.70 mmol) and 1,3-propanedithiol (361 mg, 361 L, 3.24 mmol) in dichloromethane (20 mL; dried with Aluminum oxide, activated, neutral, Brockman I) was added boron trifluoride diethyl etherate (100 L) at rt. The reaction mixture was stirred for 3 h, diluted with dichloromethane (100 mL), and extracted with 5% NaOH solution (100 mL) and water (75 mL). The organic phase was dried over MgSO4, concentrated in vacuo, and dried in high vacuo to furnish 6-[2-(5-ethoxycarbonyl-5-methyl-hexyl)-[1,3]dithian-2-yl]-2,2-dimethyl-hexanoic acid ethyl ester (1.0 g, 80%) as a yellowish oil. 1H NMR (300 MHz, CDCl3/TMS): (ppm): 4.11 (q, 4H, J=7.1), 2.79 (t, 4H, J=5.6), 1.94 (m, 2H), 1.84 (m, 4H), 1.54 (m, 4H), 1.39 (m, 4H), 1.24 (t, 6H, J=7.1), 1.30-1.20 (m, 4H), 1.16 (s, 12H). 13C NMR (75 MHz, CDCl3/TMS): (ppm): 178.08, 60.33, 53.32, 42.27, 40.69, 38.28, 26.14, 25.67, 25.28, 24.71, 14.41. HRMS (LSIMS, nba): Calcd. for C24H45S2O4 (MH4): 461.2759, found 461.2774. extracted with 5% NaOH solution (100 mL) and water (75 mL) The organic phase was dried over MgSO4 concentrated in vacuo dried in high vacuo

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

Procedure: Under N2 atmosphere, to a solution of 2,2,12,12-tetramethyl-7-oxo-tridecanedioic acid diethyl ester (1.0 g, 2.70 mmol) and 1,3-propanedithiol (361 mg, 361 L, 3.24 mmol) in dichloromethane (20 mL; dried with Aluminum oxide, activated, neutral, Brockmann I) was added boron trifluoride diethyl etherate (100 L) at rt. The reaction mixture was stirred for 3 h, diluted with dichloromethane (100 mL), and extracted with 5% NaOH solution (100 mL) and water (75 mL). The organic phase was dried over MgSO4, concentrated in vacuo, and dried in high vacuo to furnish 6-[2-(5-ethoxycarbonyl-5-methyl-hexyl)-[1,3]dithian-2-yl]-2,2-dimethyl-hexanoic acid ethyl ester (1.0 g, 80%) as a yellowish oil. 1H NMR (300 MHz, CDCl3/TMS): (ppm): 4.11 (q, 4H, J=7.1), 2.79 (t, 4H, J=5.6), 1.94 (m, 2H), 1.84 (m, 4H), 1.54 (m, 4H), 1.39 (m, 4H), 1.24 (t, 6H, J=7.1), 1.30-1.20 (m, 4H), 1.16 (s, 12H). 13C NMR (75 MHz, CDCl3/TMS): (ppm): 178.08, 60.33, 53.32, 42.27, 40.69, 38.28, 26.14, 25.67, 25.28, 24.71, 14.41. HRMS (LSIMS, nba): Calcd. for C24H45S2O4 (MH+): 461.2759. found 461.2774. extracted with 5% NaOH solution (100 mL) and water (75 mL) The organic phase was dried over MgSO4 concentrated in vacuo dried in high vacuo

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

Procedure: Under N2 atmosphere, to a solution of 2,2,12,12-tetramethyl-7-oxo-tridecanedioic acid diethyl ester (1.0 g, 2.70 mmol) and 1,3-propanedithiol (361 mg, 361 L, 3.24 mmol) in dichloromethane (20 mL; dried with Aluminum oxide, activated, neutral, Brockmann I) was added boron trifluoride diethyl etherate (100 L) at rt. The reaction mixture was stirred for 3 h, diluted with dichloromethane (100 mL), and extracted with 5% NaOH solution (100 mL) and water (75 mL). The organic phase was dried over MgSO4, concentrated in vacuo, and dried in high vacuo to furnish 6-[2-(5-ethoxycarbonyl-5-methyl-hexyl)-[1,3]dithian-2-yl]-2,2-dimethyl-hexanoic acid ethyl ester (1.0 g, 80%) as a yellowish oil. 1H NMR (300 MHz, CDCl3/TMS): (ppm): 4.11 (q, 4H, J=7.1), 2.79 (t, 4H, J=5.6), 1.94 (m, 2H), 1.84 (m, 4H), 1.54 (m, 4H), 1.39 (m, 4H), 1.24 (t, 6H, J=7.1), 1.30-1.20 (m, 4H), 1.16 (s, 12H). 13C NMR (75 MHz, CDCl3/TMS): (ppm): 178.08, 60.33, 53.32, 42.27, 40.69, 38.28, 26.14, 25.67, 25.28, 24.71, 14.41. HRMS (LSIMS, nba): Calcd. for C24H45S2O4 (MH+): 461.2759, found 461.2774. extracted with 5% NaOH solution (100 mL) and water (75 mL) The organic phase was dried over MgSO4 concentrated in vacuo dried in high vacuo

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

Procedure: Under N2 atmosphere, to a solution of 2,2,12,12-tetramethyl-7-oxo-tridecanedioic acid diethyl ester (1.0 g, 2.70 mmol) and 1,3-propanedithiol (361 mg, 361 L, 3.24 mmol) in dichloromethane (20 mL; dried with Aluminum oxide, activated, neutral, Brockmann I) was added boron trifluoride diethyl etherate (100 L) at rt. The reaction mixture was stirred for 3 h, diluted with dichloromethane (100 mL), and extracted with 5% NaOH solution (100 mL) and water (75 mL). The organic phase was dried over MgSO4, concentrated in vacuo, and dried in high vacuo to furnish 6-[2-(5-ethoxycarbonyl-5-methyl-hexyl)-[1,3]dithian-2-yl]-2,2-dimethyl-hexanoic acid ethyl ester (1.0 g, 80%) as a yellowish oil. 1H NMR (300 MHz, CDCl3/TMS): (ppm): 4.11 (q, 4H, J=7.1), 2.79 (t, 4H, J=5.6), 1.94 (m, 2H), 1.84 (m, 4H), 1.54 (m, 4H), 1.39 (m, 4H), 1.24 (t, 6H, J=7.1), 1.30-1.20 (m, 4H), 1.16 (s, 12H). 13C NMR (75 MHz, CDCl3/TMS): (ppm): 178.08, 60.33, 53.32, 42.27, 40.69, 38.28, 26.14, 25.67, 25.28, 24.71, 14.41. HRMS (LSIMS, nba): Calcd. for C24H45S2O4 (MH+): 461.2759, found 461.2774. extracted with 5% NaOH solution (100 mL) and water (75 mL) The organic phase was dried over MgSO4 concentrated in vacuo dried in high vacuo

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

Procedure: Under nitrogen atmosphere, a solution of phenyllithium (in diethyl ether:cyclohexane=30:70, 7.06 mL, 1.8 M, 12.7 mmol) was added dropwise over 10 min to a solution of methyltriphenylphosphonium iodide (5.52 g, 13.3 mmol) in anhydrous THF (40 mL) at room temperature. The reaction mixture was stirred at room temperature for 30 min, before 2,2,12,12-tetramethyl-7-oxo-tridecanedioic acid diethyl ester (4.5 g, 12.2 mmol) was added and the reaction mixture was stirred for 5 h at 50° C. The resulting light-orange mixture was quenched by adding methanol (0.3 mL), and most of the solvent was removed on a rotary evaporator. The residue was purified by chromatography on silica (hexanes:ethyl acetate=95:5) to furnish the product (2.1 g, 47%) as an oil. 1H NMR (300 MHz, CDCl3/TMS): δ (ppm): 4.67 (s, 2H), 4.10 (q, 4H, J=7.3 Hz), 1.97 (t, 4H, J=7.6 Hz), 1.6-1.3 (m, 8H), 1.30-1.15 (m, 10H), 1.15 (s, 12H). 13C NMR (75 MHz, CDCl3/TMS): δ (ppm): 178.0, 149.6, 108.6, 60.1, 42.1, 40.6, 35.8, 28.2, 25.1, 24.7, 14.2. HRMS (LSIMS, nba): Calcd. for C22H41O4 (MH+): 369.3004. found 369.3009. was added The resulting light-orange mixture was quenched by adding methanol (0.3 mL) most of the solvent was removed on a rotary evaporator The residue was purified by chromatography on silica (hexanes:ethyl acetate=95:5)

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

Procedure: Under nitrogen atmosphere, a solution of phenyllithium (in diethyl ether:cyclohexane=30:70, 7.06 mL, 1.8 M, 12.7 mmol) was added dropwise over 10 min to a solution of methyltriphenylphosphonium iodide (5.52 g, 13.3 mmol) in anhydrous THF (40 mL) at room temperature. The reaction mixture was stirred at room temperature for 30 min, before 2,2,12,12-tetramethyl-7-oxo-tridecanedioic acid diethyl ester (4.5 g, 12.2 mmol) was added and the reaction mixture was stirred for 5 h at 50° C. The resulting light-orange mixture was quenched by adding methanol (0.3 mL), and most of the solvent was removed on a rotary evaporator. The residue was purified by chromatography on silica (hexanes:ethyl acetate=95:5) to furnish the product (2.1 g, 47%) as an oil. 1H NMR (300 MHz, CDCl3/TMS): δ (ppm): 4.67 (s, 2H), 4.10 (q, 4H, J=7.3 Hz), 1.97 (t, 4H, J=7.6 Hz), 1.6-1.3 (m, 8H), 1.30-1.15 (m, 10H), 1.15 (s, 12H). 13C NMR (75 MHz, CDCl3/TMS): δ (ppm): 178.0, 149.6, 108.6, 60.1, 42.1, 40.6, 35.8, 28.2, 25.1, 24.7, 14.2. HRMS (LSIMS, nba): Calcd. for C22H41O4 (MH+): 369.3004. found 369.3009. was added The resulting light-orange mixture was quenched by adding methanol (0.3 mL) most of the solvent was removed on a rotary evaporator The residue was purified by chromatography on silica (hexanes:ethyl acetate=95:5)

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

Procedure: 7-Oxo-2,2,12,12-tetramethyltridecanedioic acid diethyl ester (9.2 g, 25 mmol) was dissolved in methanol (200 mL) and the solution was cooled in an ice-water bath. Sodium borohydride (0.95 g, 25 mmol) was added. After 2 h, another portion of sodium borohydride (0.95 g, 25 mmol) was added and stirring was continued for 2 h. The reaction mixture was hydrolyzed with water (200 mL). The aqueous solution was extracted with dichloromethane (3×150 mL). The combined organic layers were dried over magnesium sulfate and concentrated in vacuo to give the product (8.5 g, 92%) as an oil. 1H NMR (300 MHz, CDCl3/TMS): δ (ppm): 4.11 (q, 4H, J=7.0 Hz), 3.60-3.50 (m, 1H), 1.66-1.32 (m, 11H), 1.24 (pseudo-t, 12H, J=7.0 Hz), 1.15 (s, 12H). 13C NMR (75 MHz, CDCl3/TMS): δ (ppm): 178.0, 71.7, 60.1, 42.1, 40.6, 37.3, 26.0, 25.1, 24.9, 14.2. HRMS (LSIMS, nba): Calcd. for C21H41O3 (MH+): 373.2954. found: 373.2936. HPLC: 88.90% purity. the solution was cooled in an ice-water bath was continued for 2 h The aqueous solution was extracted with dichloromethane (3×150 mL) The combined organic layers were dried over magnesium sulfate concentrated in vacuo

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

Procedure: Under nitrogen atmosphere, to a suspension of lithium borohydride (2.65 g, 122 mmol) in dichloromethane (60 mL) was added methanol (4.0 g, 125 mmol) dropwise at room temperature over 30 min. The reaction mixture was heated at reflux and 2,2,12,12-tetramethyl-7-oxo-tridecanedioic acid diethyl ester (10.0 g, 27 mmol) was introduced. Heating at reflux temperature was continued overnight. The reaction mixture was cooled to room temperature and hydrolyzed with saturated ammonium chloride solution (100 mL). The layers were separated and the aqueous layer was extracted with dichloromethane (3×50 mL). The combined organic layers were washed with 2 N hydrochloric acid (100 mL) and saturated sodium chloride solution (100 mL), dried over anhydrous sodium sulfate and concentrated in vacuo to afford the crude product. The crude compound was purified by chromatography on silica (hexanes:ethyl acetate=40:60) to yield the pure product (5.8 g, 74%) as a white solid. M.p.: 72-74° C. 1H NMR (300 MHz, CDCl3/TMS): δ (ppm): 3.58 (br. m, 1H), 3.30 (s, 4H), 1.80-1.64 (m, 3H), 1.56-1.15 (m, 16H), 0.86 (s, 12H). 13C NMR. (75 MHz, CDCl3/TMS): δ (ppm): 71.87, 71.72, 38.71, 37.46, 35.11, 26.66, 24.18, 24.05, 23.97. HRMS (LSIMS, gly): Calcd. for C17H37O3 (MH+): 289.2743. found: 289.2756. HPLC: 90.6% purity. The reaction mixture was heated at reflux Heating at reflux temperature The layers were separated the aqueous layer was extracted with dichloromethane (3×50 mL) The combined organic layers were washed with 2 N hydrochloric acid (100 mL) and saturated sodium chloride solution (100 mL) dried over anhydrous sodium sulfate concentrated in vacuo to afford the crude product The crude compound was purified by chromatography on silica (hexanes:ethyl acetate=40:60)