Enantioselective total synthesis of (+)-aureol via aBF3·Et2O-promoted rearrangement/cyclizationreaction of (+)-arenarol

Abstract

(+)-Aureol (1), a structurally novel and biologically important marine natural product, was efficiently synthesized in an enantiomerically pure form starting from the known cis-fused decalin derivative 5. The synthetic method features a BF3·Et2O-promoted rearrangement/ cyclization reaction of (+)-arenarol (2) to deliver (+)-aureol (1) with complete stereoselectivity in high yield. Arenarol (2), a plausible biogenetic precursor of (+)-aureol (1), was prepared in an efficient way through; (i), a coupling reaction of 5 with 2-lithioanisole to build the requisite carbon framework 6, and (ii), salcomine oxidation of the phenolic derivative 10 to form the quinone system 11 as the crucial steps.