Total Synthesis and Structure Revision of Saniculamoid D

Abstract We present the first asymmetric total synthesis of the norsesquiterpenoid saniculamoid D, from a previously known pure chiral imide, with a longest linear sequence of seven steps. The key highlight of the synthesis is the formation of the bicyclo[3.1.0]hexane moiety through the Julia–Kocienski olefination and Hodgson cyclopropanation. Notably, the NMR spectra and specific rotation value of the synthesized structure did not agree with those of the natural compound. However, a meticulous comparison of the data prompted the reassignment of the correct structure of saniculamoid D, which now corresponds to the structure initially proposed for chromolaevanedione.