Divergent Synthesis of Marine Natural Products Siphonodictyal B, Corallidictyals C/D, and Liphagal Based on the Early Presence of an Aldehyde Group Instead of a Late-Stage Introduction.

An iodine-promoted sunlight-induced olefin Z/ E isomerization reaction together with a palladium-catalyzed direct cross-coupling reaction of a drimanal hydrazone and an iodobenzaldehyde, without touching the aromatic aldehyde group, facilitated a divergent and expeditious access to bioactive marine natural products siphonodictyal B, corallidictyals C/D, and liphagal based on the early presence of an aldehyde group instead of a late-stage introduction.