Synthesis of dihydrodehydrodiconiferyl alcohol: the revised structure of lawsonicin

Abstract
Structural revision of lawsonicin, a natural product of Lawsonia alba, is reported based upon comparison of its spectral data with that of the naturally occurring dihydrobenzo[b]furan neolignan (rac)-trans-dihydrodehydrodiconiferyl alcohol, which is found to be identical. A concise synthesis of dihydrodehydrodiconiferyl alcohol, via Rh2[S-DOSP]4 -catalysed intramolecular C–H insertion, is described.