2,6,10-trimethylundeca-5,9-dienal

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a mixture of geranylacetone (171 g) and ethyl monochloroacetate (141 g) at -10°C in the nitrogen stream, sodium ethoxide (71 g) is portionwise added, and the resultant mixture is stirred for 6 hours. A solution of potassium hydroxide (99 g) in methanol (560 ml) is added thereto, and stirring is continued for 2 hours. The reaction mixture is poured into water and skaken with petroleum ether. The water layer is neutralized with acetic acid and extracted with ether. The ether extract is washed with water and dried. After evaporation of the ether, the residual material is distilled under reduced pressure to give 2,6,10-trimethyl-5,9-undecadienal (135 g) as a pale yellow oil. B.P. 100° to 103°C/0.4 mm Hg. Yield, 73.6%. IR: 2680, 1720 cm-1 (CHO). is portionwise added extracted with ether The ether extract is washed with water dried After evaporation of the ether the residual material is distilled under reduced pressure

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A suspension of zinc (59 g) in benzene (400 ml) is heated up to the reflux temperature, and a mixture of ethyl bromoacetate (120 g) and 2,6,10-trimethyl-5,9-undecadienal (135 g) is added thereto. The resulting mixture is refluxed for 2 hours, cooled and poured into 5% aqueous solution of sulfuric acid. The benzene layer is washed with water, dried and evaporated. The residual material is distilled under reduced pressure to give ethyl 3,7,11-trimethyl-6,10-dodecadien-2-ol-1-carboxylate (100 g) as a pale yellow oil. B.P. 139° to 142°C/0.08 mm Hg. IR: 3480, 1030 cm-1 (OH); 1720, 1180cm-1 (COO). NMR (carbon tetrachloride): δ 1.25 (t), 1.58 (s), 1.65 (s), 1.95 (m), 2.38 (m), 4.10 (m), 5.05 (m). is heated up to the reflux temperature is added The resulting mixture is refluxed for 2 hours cooled The benzene layer is washed with water dried evaporated The residual material is distilled under reduced pressure