Bioinspired Semisynthesis and Structure Revisions of Chlorinated Norsesquiterpenoids Rumphellatins A-C.

The first synthesis of chlorine-containing hemiketals, rumphellatins A-C (-), previously inaccessible by means of total synthesis, was achieved starting from commercially available (-)-β-caryophyllene oxide (). Structures of rumphellatins A () and C () were revised, while structures of rumphellatin B () and intermediate rumphellolide C () were confirmed. The study expands availability of exotic norsesquiterpenoids for profiling their biological activity as well as facilitates the elucidation of biosynthetic pathways of their formation.