Stereoselective synthesis of dominicalure 1 and 2: Components of aggregation pheromone from male lesser grain borerRhyzopertha dominica (F.).

Dominicalure 1 (9a) and dominicalure 2 (9b), were synthesized by esterification of α,β-unsaturated acids4a and4b with (S)-(+)-2-pentanol (8). The key step was the asymmetric reduction of 3-penten-2-one (5) to give the chiral intermediate6, which, upon diimide reduction, DNB derivatization, recrystallization, and hydrolysis, yielded8 in 63% ee. Acids4a and4b were prepared in a simple and efficient three-step synthesis with an overall yield of 54% and 62%, respectively, in stereoisomerically pure form.