Synthèse énantiospécifique de la (+)‐( R )‐éthyl‐6‐dihydro‐2,3‐méthyl‐2‐4 H ‐pyranone‐4, phéromone de la mite Hepialus hecta L

Enantiospecific Synthesis of (+)‐( R )‐6‐Ethyl‐2,3‐dihydro‐2‐methyl‐4 H ‐pyran‐4‐one, Sex‐pheromonal Component of the Male Swift Moth Hepialus hecta L . A new synthesis of (+)−( R )‐6‐ethyl‐2,3‐dihydro‐2‐methyl‐4 H ‐pyran‐4‐one (( R )‐ 8 ), sex‐pheromonal component of the male swift moth Hepialus hecta L., has been performed from (−)‐( R )‐1‐(1,3‐dithian‐2‐yl)propan‐2‐ol with an enantiomeric excess of ⩾ 97%.