Late-Stage β-Epimerization. A Stereodivergent to Stereoconvergent Relay to the First Total Synthesis of (+)-Murolic Acid

Concise Stereoselective Synthesis of β-Hydroxy-γ-lactones: (4R,5R)-4-Hydroxy-γ-decalactone from the Japanese Orange Fly and Enantiomers of Arachnid Harvestmen Isolates

The naturally occurring (4R,5R)-4-hydroxy-γ-decalactone from the Japanese orange fly and the antipode of (4S,5R)-4-hydroxy-γ-dodecalactone from the harvestmen arachnid and their stereoisomers are synthesized from the chiral pool material d-glucono-δ-lactone in a few steps. The one-pot conversion of the latter to γ-vinyl-β-hydroxy-γ-lactone, cross-metathesis with requisite olefin, and hydrogenation enabled the synthesis of syn-lactones in just a two-pot operation. An additional efficient Pd-catalyzed allylic isomerization of γ-vinyl-β-hydroxy-γ-lactone led to the anti-lactones in high yields.

A stereoselective synthesis of the reported structure of polyporolide

A concise stereoselective synthesis of the reported structure of newly isolated acetogenin polyporolide is presented indicating a need for structure revision of the natural product.