Malyngolide Analogues. Synthesis of (${\pm}$)-Dehydromalyngolide and (${\pm}$)-Isomalyngolide

Two novel malyngolide analogues, (${\pm}$)-dehydromalyngolide and (${\pm}$)-isomalyngolide, of (-)-malyngolide antibiotic have been synthesized by application of our previously developed synthetic sequence for the synthesis of (${\pm}$)-malyngolide. Dehydromalyngolide was synthesized from the known lactone (4) in a 55 % overall yield in six steps, while isomalyngolide was synthesized from the readily available keto ester (11) in a 56 % overall yield in four steps.