Reductive elimination of acetonides, cyclic carbonates, or cyclic sulfites of γ,δ-dihydroxy (E)-α,β-unsaturated esters: an efficient route to δ-hydroxy (E)-β,γ-unsaturated esters and δ-hydroxy esters

Abstract

The acetonides, cyclic carbonates, or cyclic sulfites of γ,δ-dihydroxy (E)-α,β-unsaturated esters have been found to undergo facile reductive cleavage with samarium diiodide or magnesium in methanol to provide δ-hydroxy (E)-β,γ-unsaturated esters or δ-hydroxy esters, respectively. Using the δ-hydroxy ester 3b as a chiral synthon, (–)-5-hexadecanolide, the pheromone of the oriental hornet Vespa orientalis was synthesized.