反应详情

124 G (1M) of 6,6-dimethyl-cyclohex-2-en-1-one, 200 ml of toluene and 10 ml of trifluoro-boro-etherate are placed under nitrogen atmosphere in a three-necked reaction vessel of 1000 ml capacity equipped with a thermometer and a stirrer. The mixture was cooled to 10° and 2-methyl-penta-1,3-diene was added thereto in small portions over 4 hours. After the addition was over, the mixture was left under stirring for 1 additional hour, whereupon it was hydrolyzed with an aqueous sodium carbonate solution. The excess of toluene was removed by means of a rotary evaporator under reduced pressure and the residue was distilled to give 101.7 g of the desired product having b.p. 70°-80°/26.6 Pa. A spectroscopic analysis indicated that the product obtained consisted of about 90% of isomer cis (a) and about 10% of trans (b).

1. customequipped with a thermometer and a stirrer
2. temperatureThe mixture was cooled to 10°
3. additionAfter the addition
4. waitwas left
5. customThe excess of toluene was removed by means of a rotary evaporator under reduced pressure
6. distillationthe residue was distilled