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

HRID 1967220Notes

Reaction equation

HRID 1967220 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 δ0.80 (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 δ169.1, 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-29f72d1d47a243a6b08dfd80b8ebc7fd
Source dataset
uspto-grants-2013_04
Patent number
US08420804B2

Reaction notes

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