2,2-dimethyl-1,3-dioxan-5-ol

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

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

Procedure: To a stirring solution of 2,2-dimethyl-[1,3]dioxan-5-ol (1.50 g, 11.35 mmol), N-hydroxyphthalimide (1.85 g, 11.35 mmol) and triphenylphosphine (2.98 g, 11.35 mmol) in anhydrous tetrahydrofuran (30 mL) at 0° C. was added diethyl azodicarboxylate (2.3 mL, 14.75 mmol). The resultant solution was allowed to warm to room temperature. After stirring for 3 hours, the mixture was concentrated in vacuo and charged with chloroform affording white solids. The solids were filtered off and filtrate was collected and concentrated. The residue was purified via silica column chromatography (4:1 hexanes/ethyl acetate) affording 2-(2,2-dimethyl-[1,3]dioxan-5-yloxy)-isoindole-1,3-dione as clear crystals (1.74 g, 55% over 2 steps): 1H NMR (400 MHz; DMSO-d6) δ 7.83 (s, 4H), 4.11-4.12 (m, 1H), 4.04-4.09 (m, 2H), 3.92-3.96 (m, 2H), 1.32 (s, 3H), 1.25 (s, 3H); MS (APCI+)=278.0. the mixture was concentrated in vacuo charged with chloroform affording white solids The solids were filtered off filtrate was collected concentrated The residue was purified via silica column chromatography (4:1 hexanes/ethyl acetate)

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

Procedure: To a CH2Cl2 (200 mL) solution of 2,2-dimethyl-1,3-dioxan-5-ol (17.0 g, 0.13 mol) at 0° C., triethylamine (20 mL) was added slowly. The reaction flask was flushed with nitrogen for 5 minutes. Methacryloyl chloride (13.5 g, 0.13 mol) was added dropwise. The reaction mixture was stirred at room temperature for 3 hours, then filtered, washed with a water solution of NaHCO3 (1M, 2×200 mL) and distilled water (2×200 mL). The filtrate was dried over MgSO4. 1,4-hydroquinone (10 mg) was added as an inhibitor and solvent was removed. The oil was dissolved in ethyl acetate (50 mL) and passed through a silica gel plug. Solvent was removed and the product was purified by distillation, yielding a colorless oil product (18.5 g, 71%). 1H NMR (300 MHz, CDCl3) δ 1.38 (s, 3H), 1.41 (s, 3H), 1.92 (s, 3H), 3.77 (d, 1H), 3.82 (d, 1H), 4.05 (d, 1H), 4.10 (d, 1H), 4.71 (m, 1H), 5.56 (s, 1H), 6.12 (s, 1H). 13C NMR (75.5 MHz, CDCl3) δ 19.2, 20.6, 23.0, 61.6, 63.2, 99.3, 123.2, 124.5, 138.1. The reaction flask was flushed with nitrogen for 5 minutes filtered washed with a water solution of NaHCO3 (1M, 2×200 mL) distilled water (2×200 mL) The filtrate was dried over MgSO4 1,4-hydroquinone (10 mg) was added as an inhibitor and solvent was removed The oil was dissolved in ethyl acetate (50 mL) Solvent was removed the product was purified by distillation

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

Procedure: To a CH2Cl2 (200 mL) solution of 2,2-dimethyl-1,3-dioxan-5-ol (17.0 g, 0.13 mol) at 0° C., triethylamine (20 mL) was added slowly. The reaction flask was flushed with nitrogen for 5 minutes. Methacryloyl chloride (13.5 g, 0.13 mol) was added dropwise. The reaction mixture was stirred at room temperature for 3 hours, then filtered, washed with a water solution of NaHCO3 (1M, 2×200 mL) and distilled water (2×200 mL). The filtrate was dried over MgSO4. 1,4-hydroquinone (10 mg) was added as an inhibitor and solvent was removed. The oil was dissolved in ethyl acetate (50 mL) and passed through a silica gel plug. Solvent was removed and the product was purified by distillation, yielding a colorless oil product (18.5 g, 71%). 1H NMR (300 MHz, CDCl3) δ 1.38 (s, 3H), 1.41 (s, 3H), 1.92 (s, 3H), 3.77 (d, 1H), 3.82 (d, 1H), 4.05 (d, 1H), 4.10 (d, 1H), 4.71 (m, 1H), 5.56 (s, 1H), 6.12 (s, 1H). 13C NMR (75.5 MHz, CDCl3) δ 19.2, 20.6, 23.0, 61.6, 63.2, 99.3, 123.2, 124.5, 138.1. The reaction flask was flushed with nitrogen for 5 minutes filtered washed with a water solution of NaHCO3 (1M, 2×200 mL) distilled water (2×200 mL) The filtrate was dried over MgSO4 1,4-hydroquinone (10 mg) was added as an inhibitor and solvent was removed The oil was dissolved in ethyl acetate (50 mL) Solvent was removed the product was purified by distillation

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

Procedure: The same procedure as in the steps (6d), (6e), and (6f) of Example 6 was repeated using 2,2-dimethyl-1,3-dioxan-5-ol obtained in the step (9a) to obtain the title compound (530 mg, total yield: 18%) as a light yellow solid. obtained in the step (9a)

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

Procedure: To a diethyl ether (150 ml) solution of 2,2-dimethyl-1,3-dioxan-5-one (15 g, 0.115 mol), lithium aluminum hydride (4.38 g, 0.115 mol) was added at 0 to 8° C. for one hour in a nitrogen atmosphere. To the reaction mixture, water (4.2 ml), a 5N aqueous sodium hydroxide solution (4.2 ml), and water (12.8 ml) were sequentially added dropwise at 0 to 10° C. The mixture was dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure to obtain the title compound (14.2 g, 93.4%) as a colorless oil. The mixture was dried over anhydrous sodium sulfate filtered concentrated under reduced pressure

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

Procedure: The same procedure as in the steps (6d), (6e), and (6f) of Example 6 was repeated using 2,2-dimethyl-1,3-dioxan-5-ol obtained in the step (9a) to obtain the title compound (530 mg, total yield: 18%) as a light yellow solid. obtained in the step (9a)

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

Procedure: To a diethyl ether (150 ml) solution of 2,2-dimethyl-1,3-dioxan-5-one (15 g, 0.115 mol), lithium aluminum hydride (4.38 g, 0.115 mol) was added at 0 to 8° C. for one hour in a nitrogen atmosphere. To the reaction mixture, water (4.2 ml), a 5N aqueous sodium hydroxide solution (4.2 ml), and water (12.8 ml) were sequentially added dropwise at 0 to 10° C. The mixture was dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure to obtain the title compound (14.2 g, 93.4%) as a colorless oil. The mixture was dried over anhydrous sodium sulfate filtered concentrated under reduced pressure