反应详情

To a solution of DIBAL in dichloromethane (1.0M, 45 ml, 0.045 mol) cooled to ice bath temperature under nitrogen was added dimethyl 4,5-dimethylcyclohexa-1,4-diene-1,2-dicarboxylate (2.24 g, 0.01 mol) in dry dichloromethane (30 ml) over 30 min. The resultant solution was stirred for a further 60 mins at this temperature after which methanol (10 ml) was added. The mixture was allowed to come to room temperature, filtered through a "Celite" pad, and the filtrate concentrated in vacuo to give an oil. Crystallisation from ethyl acetate/petroleum ether (40°-60° C.) gave the title compound in 35% yield. N.m.r: δH (90 MHz, CD3OD) 4.15 (s,4H), 3.55 (bs,2H), 2.82 (s,4H), 1.69 ppm (s,6H)

1. additionwas added
2. customto come to room temperature
3. filtrationfiltered through a "Celite" pad
4. concentrationthe filtrate concentrated in vacuo
5. customto give an oil
6. customCrystallisation from ethyl acetate/petroleum ether (40°-60° C.)