Codling moth constituent synthesis

An alternative approach to the synthesis of 1,3-dienes is by elimination of benzene-sulphinic acid from homoallylic sulphones under basic conditions. This method has been used for the synthesis of a pheromone constituent of the codling moth (equation 67)109. 

The compound shown below is a constituent of the pheromone of the codling moth. It has been synthesized using n-propyl bromide, propyne, 1-pentyne, ethylene oxide, and CO2 as the source of the carbon atoms. Devise a route for such a synthesis. Hint Extensive use of the chemistry of organocopper reagents is the basis for the existing synthesis. 

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