2,6-dimethyloxan-4-one

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

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

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

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

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 1.6M methyllithium in diethyl ether (20.9 mL, 33.4 mmol) was added to a stirred slurry of copper(I) iodide (4.25 g, 22.30 mmol) in diethyl ether (30 mL) at 0° C. and under nitrogen. The reaction was stirred at 0° C. for 20 min and then racemic 2-methyl-2H-pyran-4(3H)-one (1.25 g, 11.2 mmol) in diethyl ether (12.0 mL) was added over 10 min. The reaction was allowed to warm to RT and stirred 2 h. The reaction mixture was poured into sat NH4Cl (aq) and stirred 20 min. The solution was extracted with diethyl ether (4×60 mL) and the combined organics were washed with brine (˜80 mL), dried (MgSO4), filtered and concentrated to yield racemic (2R,6R)-2,6-dimethyldihydro-2H-pyran-4(3H)-one (Cap-2, step b) (1.34 g) as an orange oil. 1H NMR (400 MHz, CDCl3) δ ppm 4.28-4.39 (m, 2H), 2.55 (ddd, J=14.1, 4.8, 1.5 Hz, 2H), 2.24 (ddd, J=14.1, 6.5, 1.5 Hz, 2H), 1.28 (d, J=6.3 Hz, 6H). to warm to RT stirred 2 h The reaction mixture was poured stirred 20 min The solution was extracted with diethyl ether (4×60 mL) the combined organics were washed with brine (˜80 mL) dried (MgSO4) filtered concentrated

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

Procedure: A solution of 2,6-dimethyl-γ-pyrone (17 g, Aldrich) in 300 mL of EtOH 95% was hydrogenated for 3 days under 70 psi. After filtration over celite, the solvent was evaporated and replaced by CH2Cl2. The solution was then treated with celite (30 g) and PCC (48.5 g). The suspension was stirred for 3 hr. and the reaction was diluted with Et2O (300 mL) and then filtered over a pad celite. The filtrate was evaporated to dryness and the residual solution was then chromatographed using hexane/Et2O (1:1) to give the title compound. After filtration over celite the solvent was evaporated The solution was then treated with celite (30 g) and PCC (48.5 g) and the reaction was diluted with Et2O (300 mL) filtered over a pad celite The filtrate was evaporated to dryness the residual solution was then chromatographed

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

Procedure: A solution of 2,6-dimethyl-γ-pyrone (17 g, Aldrich) in 300 mL of EtOH 95% was hydrogenated for 3 days under 70 psi. After filtration over celite, the solvent was evaporated and replaced by CH2Cl2. The solution was then treated with celite (30 g) and PCC (48.5 g). The suspension was stirred for 3 hr. and the reaction was diluted with Et2O (300 mL) and then filtered over a pad celite. The filtrate was evaporated to dryness and the residual solution was then chromatographed using hexane/Et2O (1:1) to give the title compound. After filtration over celite the solvent was evaporated The solution was then treated with celite (30 g) and PCC (48.5 g) and the reaction was diluted with Et2O (300 mL) filtered over a pad celite The filtrate was evaporated to dryness the residual solution was then chromatographed

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

Procedure: A solution of 1.6M methyllithium in diethyl ether (20.9 mL, 33.4 mmol) was added to a stirred slurry of copper(I) iodide (4.25 g, 22.30 mmol) in diethyl ether (30 mL) at 0° C. and under nitrogen. The reaction was stirred at 0° C. for 20 min and then racemic 2-methyl-2H-pyran-4(3H)-one (1.25 g, 11.2 mmol) in diethyl ether (12.0 mL) was added over 10 min. The reaction was allowed to warm to RT and stirred 2 h. The reaction mixture was poured into sat NH4Cl (aq) and stirred 20 min. The solution was extracted with diethyl ether (4×60 mL) and the combined organics were washed with brine (˜80 mL), dried (MgSO4), filtered and concentrated to yield racemic (2R,6R)-2,6-dimethyldihydro-2H-pyran-4(3H)-one (Cap-2, step b) (1.34 g) as an orange oil. 1H NMR (400 MHz, CDCl3) δ ppm 4.28-4.39 (m, 2H), 2.55 (ddd, J=14.1, 4.8, 1.5 Hz, 2H), 2.24 (ddd, J=14.1, 6.5, 1.5 Hz, 2H), 1.28 (d, J=6.3 Hz, 6H). to warm to RT stirred 2 h The reaction mixture was poured stirred 20 min The solution was extracted with diethyl ether (4×60 mL) the combined organics were washed with brine (˜80 mL) dried (MgSO4) filtered concentrated

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

Procedure: A solution of 2,6-dimethyl-γ-pyrone (17 g) in 300 mL of EtOH 95% was hydrogenated for 3 days under 70 psi. After filtration over celite, without extraction, the solvent was evaporated and replaced by CH2Cl2. The solution was then treated with 30 g of celite and 48.5 g of pyridinium chlorochromate. The suspension was stirred for 3 hr. and the reaction was diluted with 300 mL of Et2O and then filtered over a pad of celite. The filtrate was evaporated to dryness and the residual solution was then chromatographed using hexane/ether (1:1) to give the title compound. After filtration over celite without extraction the solvent was evaporated The solution was then treated with 30 g of celite and 48.5 g of pyridinium chlorochromate and the reaction was diluted with 300 mL of Et2O filtered over a pad of celite The filtrate was evaporated to dryness the residual solution was then chromatographed

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

Procedure: 2,6-Dimethyl-4H-pyran-4-one (4 g) was dissolved in ethanol (20 mL) and 10% Pd/C (400 mg) was added. The mixture was hydrogenated under H2 (1 atm) at room temperature for 25 hrs.

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

Procedure: A solution of 2,6-dimethyl-γ-pyrone (17 g, Aldrich) in EtOH 95% (300 mL) was hydrogenated for 3 days under 70 psi. After filtration over celite, the solvent was evaporated and replaced by CH2Cl2. The solution was then treated with celite (30 g) and PCC (48.5 g). The suspension was stirred for 3 hr. and the reaction was diluted with Et2O (300 mL) and then filtered over a pad of celite. The filtrate was evaporated to dryness and the residual solution was then chromatographed using hexane/Et2O (1:1) to give the title compound. After filtration over celite the solvent was evaporated The solution was then treated with celite (30 g) and PCC (48.5 g) and the reaction was diluted with Et2O (300 mL) filtered over a pad of celite The filtrate was evaporated to dryness the residual solution was then chromatographed