Synthesis of 5-Decenyl Acetate and Other Pheromone Components

Patent Synthesis of 5-Decenyl Acetate and Other Pheromone Components 

Pederson etal, US Patent 6,215,019 (April 10, 2001) Assignee Tillie Chemical, Inc. 

To a dry flask was added 1-hexene (2.67 mol) and bis(tricyclohexyl-phosphine) dichloro ruthenium(II)benzylidene (2.7 mmol) and the reaction stirred for 18 hours at ambient temperature. Thereafter the mixture was filtered through 200 g Silica Gel 60-200 mesh in a 1.5 X 22 chromatography column to remove the catalyst and 115 g product isolated. 

To the product from Step 1 (0.81 mol) was added 5-hexenyl acetate (0.158 mol) and bis(tricyclohexylphosphine)dichloro ruthenium(II) (1.66 mmol) and the reaction stirred for 16 hours under an 8 mm Hg vacuum. Thereafter the vacuum was removed and the mixture stirred an additional 12 hours. The product was isolated as in Step 1 in 99.4% purity consisting of a trans/cis isomeric ratio of 81 19, respectively. 

The product from Step 2 (67 mmol), 35 ml methyl alcohol, and 34 ml 2M NaOH were mixed together and stirred 3 hours at ambient temperature. Thereafter 10 ml hexane was added and the solution washed with 10 ml apiece of 1M HCl, NaHC03, and brine. The organic phase was dried, concentrated, and 9.4 g of product isolated without any change in the isomeric ratio. 

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