Hydrochloric Acid → 5-hydroxy-5-methylhexan-2-one

The obtained 2-methyl-4-(2-methyl[1,3]dioxolan-2-yl)butan-2-ol (21.18 g) was dissolved in acetone (165 ml). Thereafter, 1 M hydrochloric acid (6.6 ml) was added to the solution, and the obtained mixture was stirred at a room temperature for 2 hours. The reaction solution was neutralized with an aqueous 1 M sodium hydroxide solution. Thereafter, a saturated saline solution (100 ml) was added thereto, and acetone was then distilled off under a reduced pressure. After extraction with chloroform (200 ml×4), the organic layer was dried over anhydrous sodium sulfate. The solvent was then eliminated under a reduced pressure to obtain 5-hydroxy-5-methylhexan-2-one (14.23 g).