Pinacolone → 5-Hydroxy-2,2,6,6-tetramethyl-3-heptanone

Temperatur

-78 °C

To a solution of pinacolone (10 g, 100 mmol, 1), in anhydrous THF (500 mL), at −78° C. a 2.0 M solution of lithium diisopropylamide (LDA) in hexane (60 mL, 120 mmol) over a period of 30 min. The reaction was stirred at −78° C. for another 30 min. To the resulting white suspension pivalaldehyde (10.9 mL, 100 mmol) was added drop-wise via syringe and the reaction continued for another 12 hrs at room temperature. The reaction was quenched by adding 10 mL of water. Approximately 80% THF was removed and the mixture was then poured into saturated aqueous solution of NH4Cl. The aqueous layer was extracted twice with diethyl ether (200 mL) and the organic layer was washed with plenty of water. The organic layer was then dried over MgSO4 and concentrated to give a crude yellow solid of β-hydroxy ketone (17.2 g, 95%, (2)). The crude product was recrystallized from hexane to give pure white solid with a yield of 81%.

1. waitthe reaction continued for another 12 hrs at room temperature
2. customThe reaction was quenched
3. additionby adding 10 mL of water
4. customApproximately 80% THF was removed
5. additionthe mixture was then poured into saturated aqueous solution of NH4Cl
6. extractionThe aqueous layer was extracted twice with diethyl ether (200 mL)
7. washthe organic layer was washed with plenty of water
8. dry with materialThe organic layer was then dried over MgSO4
9. concentrationconcentrated

ORD-Eintrag

ord-0a949b82937b46d08d8550422d427c76

Quelldatensatz

uspto-grants-2014_09

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08822635B2