Neopentyl glycol → 2-Carboxy-5,5-dimethyl-1,3-dioxane

HRID 1784129Notes

Reaction equation

HRID 1784129 reaction equation
O.[C:2]([OH:6])(=[O:5])[CH:3]=[O:4].[CH3:7][C:8]([CH3:13])([CH2:11]O)[CH2:9][OH:10]>C1C=CC=CC=1>[C:2]([CH:3]1[O:10][CH2:9][C:8]([CH3:13])([CH3:11])[CH2:7][O:4]1)([OH:6])=[O:5]

Participants

4

Reactant 2

HCID 31344Neopentyl glycolHCID 15620607Glyoxylic acid, monohydrate

Product 1

HCID 114351012-Carboxy-5,5-dimethyl-1,3-dioxaneYield 73.4%

Reagents, catalysts & solvents 1

HCID 241BenzeneSolvent

Procedure

Following a general procedure,23 a mixture of glyoxylic acid monohydrate (5.0 g, 54 mmol), 2,2-dimethyl 1,3-propanediol (8.5 g, 81 mmol) and Amberlyst-15 ion-exchange resin (100 mg) in benzene (140 mL) was refluxed for 15 h in a flask fitted with a Dean-Stark apparatus. The reaction mixture was filtered. The filtrate was concentrated and then refluxed with 20% aqueous NaOH (50 mL) for 30 min. The resulting alkaline solution was extracted with ether and neutralized in the cold with dilute HCl. At the end the pH was brought to ˜1.0 using H3PO4. The acidified aqueous layer was extracted with ether. The extracts were combined, dried (Na2SO4) and concentrated to afford a white solid (6.349 g, 73%): mp 58-60° C.; 1H NMR δ 0.80 (s, 3H), 1.22 (s, 3H), 3.57 (d, J=12.0 Hz, 2H), 3.79 (d, J=12.0 Hz, 2H), 4.97 (s, 1H); 13C NMR δ 169.1, 124.7, 95.8, 77.5, 30.6, 23.0, 21.9; FAB-MS obsd 161.0806, calcd 161.0814 (C7H12O4).

Workup

  1. temperaturewas refluxed for 15 h in a flask
  2. customfitted with a Dean-Stark apparatus
  3. filtrationThe reaction mixture was filtered
  4. concentrationThe filtrate was concentrated
  5. temperaturerefluxed with 20% aqueous NaOH (50 mL) for 30 min
  6. extractionThe resulting alkaline solution was extracted with ether
  7. extractionThe acidified aqueous layer was extracted with ether
  8. dry with materialdried (Na2SO4)
  9. concentrationconcentrated

Sources & evidence

ORD record
ord-ac1066e2a00a46a68a42da26e6ac36ce
Source dataset
uspto-grants-2009_03
Patent number
US07501507B2

Reaction notes

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