Sulfuric Acid → 3,3-Dimethyl-1,5-dioxaspiro(5.5)undecan-9-one

Participants

Reaction Steps

1,4 cyclohexane dione (25.0 grams) and neopentyl glycol (23.5 grams) were dissolved in dichloromethane (200 ml). Then sulfuric acid (4.0 grams) was added to the reaction solution at an ambient temperature and stirred till the reaction substantially completes, accompanied by cooling the reaction mixture to 10–20° C. The resulting reaction mixture was washed with saturated aqueous sodium bicarbonate solution (100 ml) and separated the organic layer from the resulting biphasic mixture. The solvent was distilled off from organic layer till substantial completion under reduced pressure. n-Heptane (250 ml) was added to the resulting residual mass and followed by cooling the reaction mass to a temperature of 0–5° C. to filter the by-products. Then the solvent from the filtrate was distilled off till the substantial completion under vacuum to yield the desired 1,4 cyclohexanedione mono-2,2-dimethyl trimethylene ketal.

Provenance & Evidence