Red-Al → 2,2,3a,7-Tetramethyl-octahydro-benzofuran

Temperature

100 °C

A 3 L reaction flask was charged with vitride (325 g, 0.9 mol) and toluene (500 mL), heated to 100° C., fed with 2,6-dimethyl-2-(2-methyl-allyl)-cyclohexanone (200 g, 1.1 mol, obtained as detailed above) for over 2 hours, and aged for another 2 hours. After the reaction completed, the reaction mixture was cooled to room temperature, quenched with IPA (100 mL). NaOH (50%, 300 g) and water (200 mL) were then added, heated to 80° C., and aged for another hour. The reaction mixture was cooled to room temperature and more water (200 mL) was added. Layers were split to dispose the aqueous waste. The organic layer was charged back to the flask. Toluene (300 mL) was added and water was removed with a Bidwell-Sterling trap through azeotrope. The resulting mixture was cooled to 50° C. MSA (28 g, 0.3 mol) was added and the reaction mixture was heated to reflux. The consumption of the starting material was indicated after 3 hours. The resulting mixture was then cooled to room temperature and washed with saturated sodium carbonate solution (1 L) followed by brine (1 L). Distillation and fractionation provided the product 2,2,3a,7-tetramethyl-octahydro-benzofuran (125 g).

1. customA 3 L reaction flask
2. temperaturethe reaction mixture was cooled to room temperature
3. customquenched with IPA (100 mL)
4. additionNaOH (50%, 300 g) and water (200 mL) were then added
5. temperatureheated to 80° C.
6. waitaged for another hour
7. temperatureThe reaction mixture was cooled to room temperature
8. additionmore water (200 mL) was added
9. customLayers were split
10. additionThe organic layer was charged back to the flask
11. additionToluene (300 mL) was added
12. customwater was removed with a Bidwell-Sterling trap through azeotrope
13. temperatureThe resulting mixture was cooled to 50° C
14. additionMSA (28 g, 0.3 mol) was added
15. temperaturethe reaction mixture was heated to reflux
16. customThe consumption of the starting material
17. waitwas indicated after 3 hours
18. temperatureThe resulting mixture was then cooled to room temperature
19. washwashed with saturated sodium carbonate solution (1 L)
20. distillationDistillation and fractionation

ORD record

ord-a86a1538ee254293913fee83f8bd8f35

Source dataset

uspto-grants-2016_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09441185B2