反应详情

To a solution of the dimethyl 2-hydroxy-4-methyl-6-(3-hydroxy-3,7,11,15-tetramethyl-hexadecanyl)-benzene-1,3-dicarboxylate (5.17 g) in xylene (25 ml) at 10° was added sodium dihydrobis(2-methoxyethoxy) aluminate (20 ml of a 70% by weight solution in benzene) over 20 min with occasional cooling to keep the temperature at 10°. After 10 min the solution was heated to reflux for 1.5 hr, cooled to 10° and was poured cautiously into cold 20% by weight aqueous sulfuric acid (200 ml). The mixture was extracted with ether (3×100 ml) and the combined extracts were washed with aqueous sodium bicarbonate and brine and dried (Na2SO4) and concentrated on a rotary evaporator to give 4.29 g of crude 2,3,6-trimethyl-5-(3-hydroxy-3,7,11,15-tetramethylhexadecanyl)-phenol as a light yellow oil. Chromatography on silica gel eluting with ether in petroleum ether gave 3.19 g of pure 2,3,6-trimethyl-5-(3-hydroxy-3,7,11,15-tetramethylhexadecanyl)-phenol.

1. temperaturewith occasional cooling
2. customat 10°
3. temperatureAfter 10 min the solution was heated
4. temperatureto reflux for 1.5 hr
5. temperaturecooled to 10°
6. extractionThe mixture was extracted with ether (3×100 ml)
7. washthe combined extracts were washed with aqueous sodium bicarbonate and brine
8. dry with materialdried (Na2SO4)
9. concentrationconcentrated on a rotary evaporator