4-ethylideneoxane

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

Procedure: 3-Chloroperoxybenzoic acid (1.23 g, 7.13 mmol) was added to a solution of 4-ethylidenetetrahydro-2H-pyran (800 mg, 7.13 mmol) in dichloromethane (80 mL) at 0° C. The reaction mixture was warmed to room temperature and stirred for two hours. The mixture was diluted with dichloromethane and washed with saturated sodium bicarbonate then saturated sodium thiosulfate. The layers were separated and the aqueous layer was re-extracted with dichloromethane (2×). The combined organic layers were dried over magnesium sulfate, filtered, and concentrated under reduced pressure to afford 2-methyl-1,6-dioxaspiro[2.5]octane as a yellow oil. 1H NMR (500 MHz, CDCl3) δ 3.88-3.76 (m, 4H), 2.92 (q, J=5.5 Hz, 1H), 1.91-1.81 (m, 2H), 1.58-145 (m, 2H), 1.30 (d, J=5.5 Hz, 3H). washed with saturated sodium bicarbonate The layers were separated the aqueous layer was re-extracted with dichloromethane (2×) The combined organic layers were dried over magnesium sulfate filtered concentrated under reduced pressure

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

Procedure: 3-Chloroperoxybenzoic acid (1.23 g, 7.13 mmol) was added to a solution of 4-ethylidenetetrahydro-2H-pyran (800 mg, 7.13 mmol) in dichloromethane (80 mL) at 0° C. The reaction mixture was warmed to room temperature and stirred for two hours. The mixture was diluted with dichloromethane and washed with saturated sodium bicarbonate then saturated sodium thiosulfate. The layers were separated and the aqueous layer was re-extracted with dichloromethane (2×). The combined organic layers were dried over magnesium sulfate, filtered, and concentrated under reduced pressure to afford 2-methyl-1,6-dioxaspiro[2.5]octane as a yellow oil. 1H NMR (500 MHz, CDCl3) δ 3.88-3.76 (m, 4H), 2.92 (q, J=5.5 Hz, 1H), 1.91-1.81 (m, 2H), 1.58-145 (m, 2H), 1.30 (d, J=5.5 Hz, 3H). washed with saturated sodium bicarbonate The layers were separated the aqueous layer was re-extracted with dichloromethane (2×) The combined organic layers were dried over magnesium sulfate filtered concentrated under reduced pressure

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

Procedure: A mixture of 4-ethylidenetetrahydro-2H-pyran (about 500 mg, step 1) and 3-chloroperoxybenzoic acid (1.11 g, 4.49 mmol) in dichloromethane (50 mL) was stirred at 0° C. to room temperature for 1 h. Then, saturated aqueous sodium hydrogen carbonate solution (50 mL) and saturated aqueous sodium thiosulfate solution (50 mL) were added, and the aqueous layer was extracted with dichloromethane (100 mL×3). The combined organic layer was dried over magnesium sulfate, and concentrated in vacuo to give 337 mg of the crude title compound as a yellow oil. This was used for the next step without further purification. the aqueous layer was extracted with dichloromethane (100 mL×3) The combined organic layer was dried over magnesium sulfate concentrated in vacuo

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

Procedure: 3-Chloroperoxybenzoic acid (1.23 g, 7.13 mmol) was added to a solution of 4-ethylidenetetrahydro-2H-pyran (800 mg, 7.13 mmol) in dichloromethane (80 mL) at 0° C. The reaction mixture was warmed to room temperature and stirred for two hours. The mixture was diluted with dichloromethane and washed with saturated sodium bicarbonate then saturated sodium thiosulfate. The layers were separated and the aqueous layer was re-extracted with dichloromethane (2×). The combined organic layers were dried over magnesium sulfate, filtered, and concentrated under reduced pressure to afford 2-methyl-1,6-dioxaspiro[2.5]octane as a yellow oil. 1H NMR (500 MHz, CDCl3) δ 3.88-3.76 (m, 4H), 2.92 (q, J=5.5 Hz, 1H), 1.91-1.81 (m, 2H), 1.58-145 (m, 2H), 1.30 (d, J=5.5 Hz, 3H). washed with saturated sodium bicarbonate The layers were separated the aqueous layer was re-extracted with dichloromethane (2×) The combined organic layers were dried over magnesium sulfate filtered concentrated under reduced pressure