Total Synthesis of Elmenols A and B and Related Rearranged Angucyclinones

A short collective total synthesis of rearranged angucyclinones related to Elmenols A and B was achieved by ortho-lithiation/addition/transacetalisation sequence on the key step. Naphthalene and isocoumarine carbaldehydes required for synthesis were obtained in a straightforward manner by either of suitable methods: 1) palladium-catalyzed formylation, 2) halogen-lithium exchange, 3) decarboxylation of alpha-ketoacid.