Synthesis of (±)-lineatin by the photochemical cycloaddition of allene to anhydromevalonolactone

Abstract

(±)-Lineatin (1), the aggregation pheromone of an ambrosia beetle, was synthesized in five steps from anhydromevalonolactone (5) in 10% overall yield. The key step in the synthesis was a photochemical cycloaddition of 5 and allene. This photolysis produced two regioisomers (ca. 3:2) and efforts to improve the regioselectivity by varying the photolysis conditions or substituents on the allene were unsuccessful.[Formula: see text]