Propanal → 5-Hydroxy-4-methylheptan-3-one

HRID 1380810Notes

Reaction equation

HRID 1380810 reaction equation
[CH3:1][CH2:2][C:3](=[O:6])[CH2:4][CH3:5].[OH-].[K+].[CH:9](=O)CC.[C:13]([OH:18])(=O)[C:14](O)=O>CO>[CH3:1][CH2:2][C@@H:3]([OH:6])[C@@H:4]([C:13]([CH2:14][CH3:9])=[O:18])[CH3:5]

Participants

6

Reactant 4

HCID 527PropanalHCID 971Oxalic AcidHCID 7288Ethyl ketone2×HCID 14797Potassium Hydroxide2×

Product 1

HCID 1556635-Hydroxy-4-methylheptan-3-one

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Conditions

Temperature
15 °C

Procedure

A 1-liter, 2-necked flask equipped with a dropping funnel, thermometer, and magnetic stirrer was charged with 344.0 g. (4 moles) of freshly distilled 3-pentanone. After cooling the apparatus to 15° C., an addition was made of 30.6 ml. of 16.8% (w/w) potassium hydroxide in methanol. This was followed by dropwise addition over 4 hrs. of 58.0 g. (1 mole) of freshly distilled propionaldehyde mixed with another 172.0-g. lot of 3-pentanone. Stirring was continued for an additional 30 min. after which the base (KOH) was neutralized with 3.5 g. of anhydrous oxalic acid. The solution was filtered and then distilled under vacuum to remove unreacted 3-pentanone and methanol. The aldol distilled at 70° C. (0.45 mm.) and yielded 66.7 g. (46% based on propionaldehyde). The distribution of R*S* and R*R* diastereomers was approximately 1:1.

Workup

  1. customA 1-liter, 2-necked flask equipped with a dropping funnel
  2. additionthermometer, and magnetic stirrer was charged with 344.0 g
  3. additionan addition
  4. additionThis was followed by dropwise addition over 4 hrs
  5. filtrationThe solution was filtered
  6. distillationdistilled under vacuum
  7. customto remove unreacted 3-pentanone and methanol
  8. distillationThe aldol distilled at 70° C. (0.45 mm.)
  9. customyielded 66.7 g

Sources & evidence

ORD record
ord-7c7aaa02eadc48fbb29257466918f115
Source dataset
uspto-grants-1986_04
Patent number
US04584193

Reaction notes

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