Glyoxal → 6-Ethoxy-3-methyl-3,6-dihydro-2H-pyran-2-carbaldehyde

HRID 28083

Reaction equation

HRID 28083 reaction equation
[CH:1]([CH:3]=[O:4])=[O:2].O.C(C=O)=O.O=P12OP3(OP(OP(O3)(O1)=O)(=O)O2)=O.[CH2:24]([O:26][CH:27]=[CH:28][CH:29]=[CH:30][CH3:31])[CH3:25].O1C=CC=CC1>>[CH3:31][CH:30]1[CH:29]=[CH:28][CH:27]([O:26][CH2:24][CH3:25])[O:2][CH:1]1[CH:3]=[O:4]

Participants

6

Reactant 5

HCID 7860GlyoxalHCID 14812Phosphorus oxide (P4O10)HCID 186148PyranHCID 21880647Glyoxal hydrateHCID 537696421-Ethoxy-1,3-pentadiene

Product 1

HCID 205713736-Ethoxy-3-methyl-3,6-dihydro-2H-pyran-2-carbaldehyde

Procedure

Monomeric glyoxal was generated by heating a mixture of 8.0 g. of glyoxal hydrate (0.117 mol. of monomer) and 48.0 g. of phosphorus pentoxide over a gentle flame over 35 minutes. The liberated monomer was bubbled (argon stream) into 4.8 g. (0.04 mol) of 1-ethoxy-1,3-pentadiene (purity 92.3%) at 120°. After all the monomer had been generated, the solution was heated at 120° for an additional 45 minutes. Distillation afforded 1.32 g. of the pyran (b0.07 =56°, purity 91%) and 1.86 g. of recovered diene (yield based on diene-32%, based on glyoxal=6.6%).

Workup

  1. temperatureby heating
  2. additiona mixture of 8.0 g
  3. customThe liberated monomer was bubbled (argon stream) into 4.8 g
  4. customat 120°
  5. temperaturethe solution was heated at 120° for an additional 45 minutes
  6. distillationDistillation
  7. customafforded 1.32 g

Sources & evidence

ORD record
ord-2366a6ae4634412587007d52d3c06a6a
Source dataset
uspto-grants-1980_09
Patent number
US04225514

Linked notes

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