Diethyl Ether → 5,9,13-Trimethyltetradeca-4,6-dien-3-one

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Reaction Steps

To a solution of 3.00 g. of trans/cis 3,7,11-trimethyldodeca-2,4-dienoic acid in 50 ml. ether at 0° under nitrogen is added 28.00 ml. of 0.9 M solution of ethyllithium in benzene. The solution is stirred for 1/2 hour at 0° and then overnight at room temperature. To the reaction mixture is added 50 ml. of ether and the resultant solution is added dropwise with stirring to 300 ml. saturated aqueous ammonium chloride. The organic layer is separated and is washed in turn with 50 ml. saturated aqueous ammonium chloride, 35 ml. water, and 35 ml. saturated aqueous sodium chloride. The solution is dried over calcium sulfate, is concentrated and is then purified by preparative thin layer chromatography (1:3 ether/hexane) and short path distillation (boiling point 100° at .18 mm.) to give 5,9,13-trimethyltetradeca-4,6-dien-3-one (85.4% trans-4, trans-6; 14.6% cis-4, trans-6.).

Provenance & Evidence