Terpenoid Chemistry. XXIX. (-)-Anymol From Myoporum crassifolium Forst, the C7 Epimer of (-)-α-Bisabolol From Camomile

Abstract

The conflicting literature on the configurations of (-)-anymol, the major sesquiterpene alcohol of Myoporum crassifolium wood oil, and the α-bisabolols, is critically reviewed. (-)-Anymol [p-phenylazophenylurethane m.p. 105º, [α]D -7º (CHCl₃/1% EtOH)] is shown to be the C7 epimer (farnesol numbering) of (-)-6S,7S-α-bisabolol (-)-2S,1′S-6-methyl-2-(4′methyl-cyclohex-3′-enyl)hept-5-en-2-ol] (p-phenylazophenylurethane, m.p. 129º, [α]D-0.8º) from Vanillosmopsis eryrhropappa Sch.-Bip. wood oil and hence also of the (-)-α-bisabolol from Matricaria charnomilla L. leaf oil. However the m.p. 104º and 17.7º ascribed by Babin, Fourneron and Julia to their p-phenylazophenylurethane of chamomile-derived (-)-α-bisabolol are anomalous despite the generation of the appropriate structure by X-ray diffraction.