2-Oxepanone, 5,5-dimethyl- synthesis

Yield:60187-76-0 100%

Reaction Conditions:

Stage #1: 4,4-dimethylcyclohexan-1-onewith 3-chloro-benzenecarboperoxoic acid in dichloromethane at 20; for 48 h;
Stage #2: with anhydrous sodium carbonate;Na₂S₂O₃ in lithium hydroxide monohydrate at 0; for 0.166667 h;

Steps:

121.1 Step 1: 5,5-Dimethyloxepan-2-one

To a solution of 4,4-dimethylcyclohexanone (6.1 g, 48.338 mmol) in dichloromethane (120 mL) was added meta-chloroperoxybenzoic acid (17.5 g, 75 % w/w, 76.058 mmol). The mixture was stirred in the dark at room temperature for 2 days and filtered. The cake was washed with dichloromethane-pentane (1:1, 20 mL). The filtrate was added to a mixture of sodium carbonate (6 g, 56 mmol), water (50 mL) and 10 % aqueous sodium thiosulfate (50 mL) at 0 °C. The resulting mixture was stirred at 0 °C for 10 min and transferred to a separatory funnel. The organic layer was washed with saturated NaHCO₃ (50 mL) and brine (20 mL) and dried with Na₂SO₄, filtered and concentrated to give as a white solid, 5,5-dimethyloxepan-2-one (6.87 g, 100 %). ¹H NMR (400 MHz, CDCl₃) δ 4.22 - 4.18 (m, 2H), 2.62 - 2.58 (m, 2H), 1.67 - 1.63 (m, 2H), 1.58 - 1.54 (m, 2H), 1.02 (s, 6H). ESI-MS m/z calc. 142.0994, found 143.2 (M+1)⁺; Retention time: 1.54 minutes. (LC Method E).

References:

WO2022/109573,2022,A1 Location in patent:Paragraph 001179