A novel synthesis of the aggregation pheromone of the Colorado potato beetle, Leptinotarsa decemlineata, has been developed based on a Sharpless asymmetric epoxidation in combination with a chemoselective alcohol oxidation using catalytic [(neocuproine)PdOAc]2OTf2. Employing this approach, the pheromone was synthesized in 3 steps, 80% yield and 86% ee from geraniol.
An efficient catalytic asymmetric synthesis of the CPB pheromone [(S)-1,3-dihydroxy-3,7-dimethy1-6-octen-2-one] and its enantiomer was accomplished with 99% ee and in gram quantities from geraniol. The key steps in this procedure involve Sharpless asymmetric epoxidation and recrystallization of the 4-bromobenzoate from the CPB pheromone to improve its enantiomeric purity. Furthermore, the absolute configuration of the CPB pheromone enantiomer was confirmed as (R) for the first time by the X-ray crystallographic structure of its benzoate. (C) 2014 Elsevier Ltd. All rights reserved.
Enantioselective synthesis of (S)-3,7-dimethyl-2-oxo-6-octene-1,3-diol: a Colorado potato beetle pheromone
作者:Bathini Nagendra Babu、Kamlesh R. Chauhan
DOI:10.1016/j.tetlet.2008.10.092
日期:2009.1
The recent identification of a male-produced aggregation pheromone [(S)-3,7-dimethyl-2-oxo-6-octene1,3-diol, (S)-CPB] offers a new tool for Colorado potato beetle (CPB) management. We developed a novel synthetic approach to produce CPB pheromone in seven steps and 46.54% overall yield. Grignard reaction, oxidation, and stereoselective methylation using organometallic reagent are the key steps in the commercially viable total synthesis, generating CPB pheromone in 98.6% enantiomeric purity and gram quantity. Published by Elsevier Ltd.
Synthesis of the aggregation pheromone of the Colorado potato beetle from its degradation product
Incubation of the Colorado potato beetleaggregationpheromone, (S)-1,3-dihydroxy-3,7-dimethyl-6-octen-2-one, with antennal or leg extracts from this beetle gave 6-methyl-5-hepten-2-one as the major product. This ketone was used as a substrate in a stereoselective synthesis of the pheromone. It was attached to the butanediacetal of glycolic acid with good stereoselectivity and the desired isomer was