(2R,4R)-pentane-2,4-diol

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

Procedure: A mixture of 2-methylcyclohexanone (13.1 g), (2R,4R)-2,4-pentanediol (12.2 g), pyridinium p-toluene sulfonate (119 mg) and toluene (120 ml) was refluxed with heating for 8 hours. The reaction mixture was added with a saturated aqueous solution of sodium hydrogen carbonate, extracted with diethyl ether, the organic layer was dried over sodium sulfate and the solvent was evaporated under reduced pressure. The residue was purified by silica gel chromatography (elution solvent: hexane/ethyl acetate=100/0 to 0/100 gradient) to obtain 18.0 g of (2R,4R)-2,4,7-trimethyl-1,5-dioxaspiro[5.5]undecane was refluxed with heating for 8 hours extracted with diethyl ether the organic layer was dried over sodium sulfate the solvent was evaporated under reduced pressure The residue was purified by silica gel chromatography (elution solvent: hexane/ethyl acetate=100/0 to 0/100 gradient)

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

Procedure: A solution of (2R,4R)-2,4-pentanediol (15.0 g), triethylamine (45.2 mL) and dichloromethane (350 mL) is cooled at a temperature close to 0° C. Methanesulfonyl chloride (24.5 mL) is added dropwise. The mixture is stirred for 3 h at a temperature close to 0° C., hydrolysed with a 1.5 N aqueous hydrochloric solution (100 mL) and extracted with dichloromethane. The organic extracts are pooled, washed with a saturated aqueous solution of sodium hydrogenocarbonate, then a saturated aqueous solution of sodium chloride, dried over magnesium sulphate and concentrated under reduced pressure to give 36.06 g of (2R,4R)-2,4-pentanediol dimethanesulfonate as a brown oil used without further purification. close to 0° C extracted with dichloromethane washed with a saturated aqueous solution of sodium hydrogenocarbonate a saturated aqueous solution of sodium chloride, dried over magnesium sulphate concentrated under reduced pressure

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

Procedure: After phenol (300 mg, 3.19 mmol), triphenylphosphine (1006 mg, 3.83 mmol), (2R,4R)-2,4-pentanediol (399 mg, 3.83 mmol), and THF (12 ml) were added to a 50 ml flask, a 40% azodicarboxylic acid diisopropyl ester-toluene solution (2.01 ml, 3.83 mmol) dissolved in THF (6 ml) was added dropwise thereto at 20° C., and the reaction was allowed to proceed for 21 hours. Water (0.5 ml) was added, and concentration was carried out. Then, water (10 ml) was added to the solution, and extraction was carried out using diethyl ether (10 ml, ×2). Then, the organic layer was washed with water (10 ml) and saturated salt water (10 ml), and dehumidified with anhydrous magnesium sulfate. Subsequently, a crude product obtained by concentration was purified by column chromatography (silica gel, 40% ethyl acetate-hexane solution) to give (4S,2R)-4-phenoxypentane-2-ol as a colorless oily substance (461 mg, yield: 80%/phenol). was added dropwise at 20° C. concentration Then, water (10 ml) was added to the solution, and extraction Then, the organic layer was washed with water (10 ml) and saturated salt water (10 ml) Subsequently, a crude product obtained by concentration was purified by column chromatography (silica gel, 40% ethyl acetate-hexane solution)

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

Procedure: After phenol (300 mg, 3.19 mmol), triphenylphosphine (1008 mg, 3.83 mmol), (2R,4R)-2,4-pentanediol (399 mg, 3.83 mmol), and THF (12 ml) were added to a 50 ml flask, azodicarboxylic acid bis(2-methoxyethyl) ester (896 mg, 3.83 mmol) dissolved in THF (6 mL) was added dropwise thereto at 20° C., and the reaction was allowed to proceed for 21 hours. Water (0.5 ml) was added, and concentration was carried out. Then, water (10 ml) was added to the solution, and extraction was carried out using diethyl ether (10 ml, ×2). Then, the organic layer was washed with water (10 ml) and saturated salt water (10 ml), and dehumidified with anhydrous magnesium sulfate. Subsequently, a crude product obtained by concentration was purified by column chromatography (silica gel, 40% ethyl acetate-hexane solution) to give (4S,2R)-4-phenoxypentane-2-ol as a colorless oily substance (481 mg, yield: 84%/phenol). was added dropwise at 20° C. concentration Then, water (10 ml) was added to the solution, and extraction Then, the organic layer was washed with water (10 ml) and saturated salt water (10 ml) Subsequently, a crude product obtained by concentration was purified by column chromatography (silica gel, 40% ethyl acetate-hexane solution)

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

Procedure: After phenol (300 mg, 3.19 mmol), triphenylphosphine (1008 mg, 3.83 mmol), (2R,4R)-2,4-pentanediol (399 mg, 3.83 mmol), and THF (12 ml) were added to a 50 ml flask, azodicarboxylic acid bis(2-methoxyethyl) ester (896 mg, 3.83 mmol) dissolved in THF (6 mL) was added dropwise thereto at 20° C., and the reaction was allowed to proceed for 21 hours. Water (0.5 ml) was added, and concentration was carried out. Then, water (10 ml) was added to the solution, and extraction was carried out using diethyl ether (10 ml, ×2). Then, the organic layer was washed with water (10 ml) and saturated salt water (10 ml), and dehumidified with anhydrous magnesium sulfate. Subsequently, a crude product obtained by concentration was purified by column chromatography (silica gel, 40% ethyl acetate-hexane solution) to give (4S,2R)-4-phenoxypentane-2-ol as a colorless oily substance (481 mg, yield: 84%/phenol). was added dropwise at 20° C. concentration Then, water (10 ml) was added to the solution, and extraction Then, the organic layer was washed with water (10 ml) and saturated salt water (10 ml) Subsequently, a crude product obtained by concentration was purified by column chromatography (silica gel, 40% ethyl acetate-hexane solution)

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

Procedure: After 4-methoxyphenol (300 mg, 2.41 mmol), triphenylphosphine (762 mg, 2.89 mmol), (2R,4R)-2,4-pentanediol (303 mg, 2.89 mmol), and THF (12 ml) were added to a 50 ml flask, a 40% azodicarboxylic acid diisopropyl ester-toluene solution (1.53 mL, 2.89 mmol) dissolved in THF (6 ml) was added dropwise thereto at 20° C., and the reaction was allowed to proceed for 17 hours. Water (0.5 ml) was added, and concentration was carried out. Then, water (10 ml) was added to the solution, and extraction was carried out using diethyl ether (10 ml, ×2). Then, the organic layer was washed with water (10 ml) and saturated salt water (10 ml), and dehumidified with anhydrous magnesium sulfate. Subsequently, a crude product obtained by concentration was purified by column chromatography (silica gel, 30% ethyl acetate-hexane solution) to give (4S,2R)-4-(4-methoxyphenoxy)pentane-2-ol containing 1,2-hydrazinedicarboxylic acid diisopropyl ester as 543 mg of a colorless oily substance. Measurement of 1H-NMR showed that 420 mg of (4S,2R)-4-benzoyloxypentane-2-ol (yield: 83%/4-methoxyphenol), and 123 mg of 1,2-hydrazinedicarboxylic acid diisopropyl ester were contained. was added dropwise at 20° C. concentration Then, water (10 ml) was added to the solution, and extraction Then, the organic layer was washed with water (10 ml) and saturated salt water (10 ml) Subsequently, a crude product obtained by concentration was purified by column chromatography (silica gel, 30% ethyl acetate-hexane solution)

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

Procedure: After 4-methoxyphenol (300 mg, 2.41 mmol), triphenylphosphine (761 mg, 2.89 mmol), (2R,4R)-2,4-pentanediol (302 mg, 2.89 mmol), and THF (12 mL) were added to a 50 ml flask, azodicarboxylic acid bis(2-methoxyethyl) ester (680 mg, 2.89 mmol) dissolved in THF (6 ml) was added dropwise thereto at 20° C., and the reaction was allowed to proceed for 14 hours. Water (0.5 ml) was added, and concentration was carried out. Then, water (10 ml) was added to the solution, and extraction was carried out using diethyl ether (10 mL, ×2). Then, the organic layer was washed with water (10 ml) and saturated salt water (10 ml), and dehumidified with anhydrous magnesium sulfate. Subsequently, a crude product obtained by concentration was purified by column chromatography (silica gel, 30% ethyl acetate-hexane solution) to give (4S,2R)-4-(4-methoxyphenoxy)pentane-2-ol as a colorless oily substance (418 mg, yield: 82%/4-methoxyphenol). was added dropwise at 20° C. concentration Then, water (10 ml) was added to the solution, and extraction Then, the organic layer was washed with water (10 ml) and saturated salt water (10 ml) Subsequently, a crude product obtained by concentration was purified by column chromatography (silica gel, 30% ethyl acetate-hexane solution)

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

Procedure: After 4-methoxyphenol (300 mg, 2.41 mmol), triphenylphosphine (761 mg, 2.89 mmol), (2R,4R)-2,4-pentanediol (302 mg, 2.89 mmol), and THF (12 mL) were added to a 50 ml flask, azodicarboxylic acid bis(2-methoxyethyl) ester (680 mg, 2.89 mmol) dissolved in THF (6 ml) was added dropwise thereto at 20° C., and the reaction was allowed to proceed for 14 hours. Water (0.5 ml) was added, and concentration was carried out. Then, water (10 ml) was added to the solution, and extraction was carried out using diethyl ether (10 mL, ×2). Then, the organic layer was washed with water (10 ml) and saturated salt water (10 ml), and dehumidified with anhydrous magnesium sulfate. Subsequently, a crude product obtained by concentration was purified by column chromatography (silica gel, 30% ethyl acetate-hexane solution) to give (4S,2R)-4-(4-methoxyphenoxy)pentane-2-ol as a colorless oily substance (418 mg, yield: 82%/4-methoxyphenol). was added dropwise at 20° C. concentration Then, water (10 ml) was added to the solution, and extraction Then, the organic layer was washed with water (10 ml) and saturated salt water (10 ml) Subsequently, a crude product obtained by concentration was purified by column chromatography (silica gel, 30% ethyl acetate-hexane solution)

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

Procedure: After benzoic acid (300.6 mg, 2.46 mmol), triphenylphosphine (776.2 mg, 2.95 mmol), (2R,4R)-2,4-pentanediol (309.1 mg, 2.95 mmol), and THF (12 mL) were added to a 50 ml flask, a 40% azodicarboxylic acid diisopropyl ester-toluene solution (1.55 ml, 2.95 mmol) dissolved in THF (6 ml) was added dropwise thereto at 20° C., and the reaction was allowed to proceed for ix hours. Water (0.5 ml) was added, and concentration was carried out. Then, water (10 ml) was added to the solution, and extraction was carried out using diethyl ether (10 ml, ×2). Then, the organic layer was washed with water (10 ml) and saturated salt water (10 ml), and dehumidified with anhydrous magnesium sulfate. Subsequently, a crude product obtained by concentration was purified by column chromatography (silica gel, 40% ethyl acetate-hexane solution) to give (4S,2R)-4-benzoyloxypentane-2-ol containing 1,2-hydrazinedicarboxylic acid diisopropyl ester as 525.3 mg of a colorless oily substance. Measurement of 1H-NMR showed that 380 mg of (4S,2R)-4-benzoyloxypentane-2-ol (yield: 74%/benzoic acid), and 146 mg of 1,2-hydrazinedicarboxylic acid diisopropyl ester were contained. was added dropwise at 20° C. concentration Then, water (10 ml) was added to the solution, and extraction Then, the organic layer was washed with water (10 ml) and saturated salt water (10 ml) Subsequently, a crude product obtained by concentration was purified by column chromatography (silica gel, 40% ethyl acetate-hexane solution)

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

Procedure: After benzoic acid (300 mg, 2.46 mmol), triphenylphosphine (775 mg, 2.95 mmol), (2R,4R)-2,4-pentanediol (308 mg, 2.95 mmol), and THF (12 ml) were added to a 50 ml flask, azodicarboxylic acid bis(2-methoxyethyl) ester (691.1 mg, 2.95 mmol) dissolved in THF (6 mL) was added dropwise thereto at 20° C., and the reaction was allowed to proceed for one hour. Water (0.5 ml) was added, and concentration was carried out. Then, water (10 ml) was added to the solution, and extraction was carried out using diethyl ether (10 mL, ×2). Then, the organic layer was washed with water (10 ml) and saturated salt water (10 ml), and dehumidified with anhydrous magnesium sulfate. Subsequently, a crude product obtained by concentration was purified by column chromatography (silica gel, 40% ethyl acetate-hexane solution) to give (4S,2R)-4-benzoyloxypentane-2-ol as a colorless oily substance (379 mg, yield: 74%/benzoic acid). was added dropwise at 20° C. concentration Then, water (10 ml) was added to the solution, and extraction Then, the organic layer was washed with water (10 ml) and saturated salt water (10 ml) Subsequently, a crude product obtained by concentration was purified by column chromatography (silica gel, 40% ethyl acetate-hexane solution)

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

Procedure: After triphenylphosphine (566 mg, 2.16 mmol), (2R,4R)-2,4-pentanediol (225 mg, 2.16 mmol), and THF (6 ml) were added to a 50 mL flask, a 40% azodicarboxylic acid diisopropyl ester-toluene solution (1.13 mL, 2.16 mmol) dissolved in THF (6 mL) was added dropwise thereto at 20° C. Subsequently, 4-nitrobenzoic acid (300 mg, 1.80 mmol) dissolved in THF (6 mL) was added dropwise thereto at 20° C., and the reaction was allowed to proceed for one hour. Water (0.5 ml) was added, and concentration was carried out. Then, water (10 ml) was added to the solution, and extraction was carried out using diethyl ether (10 mL, ×2). Then, the organic layer was washed with water (10 ml) and saturated salt water (10 ml), and dehumidified with anhydrous magnesium sulfate. Subsequently, a crude product obtained by concentration was purified by column chromatography (silica gel, 40% ethyl acetate-hexane solution) to give (4S,2R)-4-benzoyloxypentane-2-ol containing 1,2-hydrazinedicarboxylic acid diisopropyl ester as 593 mg of a pale yellow solid substance. Measurement of 1H-NMR showed that 379 mg of (4S,2R)-4-(4-nitrobenzoyloxy)pentane-2-ol (yield: 83%/4-nitrobenzoic acid), and 213 mg of 1,2-hydrazinedicarboxylic acid diisopropyl ester were contained. was added dropwise at 20° C was added dropwise at 20° C. concentration Then, water (10 ml) was added to the solution, and extraction Then, the organic layer was washed with water (10 ml) and saturated salt water (10 ml) Subsequently, a crude product obtained by concentration was purified by column chromatography (silica gel, 40% ethyl acetate-hexane solution)

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

Procedure: After triphenylphosphine (566 mg, 2.16 mmol), (2R,4R)-2,4-pentanediol (225 mg, 2.16 mmol), and THF (6 ml) were added to a 50 mL flask, a 40% azodicarboxylic acid diisopropyl ester-toluene solution (1.13 mL, 2.16 mmol) dissolved in THF (6 mL) was added dropwise thereto at 20° C. Subsequently, 4-nitrobenzoic acid (300 mg, 1.80 mmol) dissolved in THF (6 mL) was added dropwise thereto at 20° C., and the reaction was allowed to proceed for one hour. Water (0.5 ml) was added, and concentration was carried out. Then, water (10 ml) was added to the solution, and extraction was carried out using diethyl ether (10 mL, ×2). Then, the organic layer was washed with water (10 ml) and saturated salt water (10 ml), and dehumidified with anhydrous magnesium sulfate. Subsequently, a crude product obtained by concentration was purified by column chromatography (silica gel, 40% ethyl acetate-hexane solution) to give (4S,2R)-4-benzoyloxypentane-2-ol containing 1,2-hydrazinedicarboxylic acid diisopropyl ester as 593 mg of a pale yellow solid substance. Measurement of 1H-NMR showed that 379 mg of (4S,2R)-4-(4-nitrobenzoyloxy)pentane-2-ol (yield: 83%/4-nitrobenzoic acid), and 213 mg of 1,2-hydrazinedicarboxylic acid diisopropyl ester were contained. was added dropwise at 20° C was added dropwise at 20° C. concentration Then, water (10 ml) was added to the solution, and extraction Then, the organic layer was washed with water (10 ml) and saturated salt water (10 ml) Subsequently, a crude product obtained by concentration was purified by column chromatography (silica gel, 40% ethyl acetate-hexane solution)