Water → 3-Ethylbicyclo[3.2.0]hept-3-en-6-one

Temperatur

110 °C

(2E)-4-Ethylhepta-2,6-dienoic acid (34.0 g, purity: 90.7%) was dissolved in N,N-dimethylacetamide (100 mL) under the nitrogen atmosphere. To the solution, acetic anhydride (37.8 mL, 0.40 mol) and triethylamine (28 mL, 0.20 mol) were added. The reaction mixture was warmed and stirred at 105 to 115° C. for 6.5 hours. The reaction mixture was cooled to room temperature, and water (200 mL) was added thereto, followed by four extractions with n-hexane (150 mL×2 and 50 mL×2). All the extracted organic layers were combined and then washed with a saturated aqueous solution of sodium bicarbonate (50 mL) and water (50 mL) in this order. The obtained organic layer was concentrated under reduced pressure, and the residue was distilled under reduced pressure (93-102° C., approximately 25 mmHg) to obtain the title compound (22.06 g, colorless oil substance) (yield: 81%).

1. temperatureThe reaction mixture was warmed
2. temperatureThe reaction mixture was cooled to room temperature
3. extractionfollowed by four extractions with n-hexane (150 mL×2 and 50 mL×2)
4. washwashed with a saturated aqueous solution of sodium bicarbonate (50 mL) and water (50 mL) in this order
5. concentrationThe obtained organic layer was concentrated under reduced pressure
6. distillationthe residue was distilled under reduced pressure (93-102° C., approximately 25 mmHg)

ORD-Eintrag

ord-813320f04b4442daab54809b85247511

Quelldatensatz

uspto-grants-2015_12

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US09206104B2