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

HRID 1826214Notes

Reaction equation

HRID 1826214 reaction equation
[C:1]1(=[O:8])[CH2:6][CH2:5][C:4](=[O:7])[CH2:3][CH2:2]1.[OH:9][CH2:10][C:11]([CH3:15])([CH2:13]O)[CH3:12].S(=O)(=O)(O)O>ClCCl>[CH3:12][C:11]1([CH3:15])[CH2:10][O:9][C:4]2([CH2:5][CH2:6][C:1](=[O:8])[CH2:2][CH2:3]2)[O:7][CH2:13]1

Participants

5

Reactant 3

HCID 1118Sulfuric AcidHCID 125111,4-CyclohexanedioneHCID 31344Neopentyl glycol

Product 1

HCID 5879683,3-Dimethyl-1,5-dioxaspiro(5.5)undecan-9-one

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

1,4 cyclohexane dione (20.0 grams) and neopentyl glycol (18.6 grams) were dissolved in dichloromethane (160 ml). Then sulfuric acid (3.2 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 (80 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. Hexane (200 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.

Workup

  1. temperatureby cooling the reaction mixture to 10–20° C
  2. customThe resulting reaction mixture
  3. washwas washed with saturated aqueous sodium bicarbonate solution (80 ml)
  4. customseparated the organic layer from the resulting biphasic mixture
  5. distillationThe solvent was distilled off from organic layer till substantial completion under reduced pressure
  6. additionHexane (200 ml) was added to the resulting residual mass
  7. temperatureby cooling the reaction mass to a temperature of 0–5° C.
  8. filtrationto filter the by-products
  9. distillationThen the solvent from the filtrate was distilled off till the substantial completion under vacuum

Sources & evidence

ORD record
ord-bd8ab25786134855b0732524f03b9358
Source dataset
uspto-grants-2006_05
Patent number
US07049448B2

Reaction notes

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