Synthetic Studies on Leptolyngbyalides A–C: Stereoselective Synthesis of the C1–C15 Fragment

We describe herein a stereoselective synthesis of the C1–C15 fragment of leptolyngbyalides A–C. A stereochemically modular synthesis of the C4–C12 domain harboring the configurationally unassigned C5, C7, and C9 stereogenic centers was achieved by taking advantage of chiral auxiliary-assisted diastereoselective reactions. Subsequent transformations including an aldol coupling, a Narasaka–Prasad reduction, and a Suzuki–Miyaura coupling completed the synthesis of the C1–C15 fragment, corresponding to an open-chain form of the macrocyclic skeleton of of leptolyngbyalides A–C.