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

関与物質

反応条件

反応手順

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).

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