Asymmetric Syntheses of the Sex Pheromones of Pine Sawflies, Their Homologs and Stereoisomers

We describe efficient and flexible enantioselective syntheses of the active enantiomers of the pheromones of pine sawflies, including the species Diprion jingyuanensis , their homologs and, stereoisomers, as well as those identified from the Chinese species Diprion jingyuanensis, i.e. , 126 . A total of 48 compounds, including acetates 78 – 101 and propanoates 102 – 125 , have been synthesized. Our general approach towards these compounds originated from the commercially available chirons diethyl ( S )‐ and ( R )‐malates, as well as ethyl ( R )‐3‐hydroxybutanoate. The Seebach asymmetric methylation was employed in a key step to control additional configuration.