Cover Picture: Ring Reversal of a Spirocyclic Patchouli Odorant: Molecular Modeling, Synthesis, and Odor of 6‐Hydroxy‐1,1,6‐trimethylspiro[4.5]decan‐7‐one (Eur. J. Org. Chem. 14/2007)

Abstract The cover picture shows shows the superposition of two spirocyclic target molecules, modeled on a recently discovered high‐impact patchouli odorant by ring‐reversal and structural simplification. Yet, despite omission of two methyl substituents, these sterically congested structures proved to be synthetically challenging targets. The synthesis of the first and principal target features a TiCl 4 ‐mediated spiroannulation of the TMS‐enolate of cyclohexanone with 1‐bromo‐4‐chloro‐4‐methylpentane, subsequent dehydration by Appel–Lee bromination with concomitant dehydrohalogenation, and the elegant ketohydroxylation reaction of Plietker. Key odor descriptors for “ patchouli ” are “ camphor ”, “ woody ” and “ earthy ”, and depending on the molecular shape of the odorants, these are more or less balanced; the first target structure, for instance, is more shifted towards the camphoraceous, in principle an anti‐erogenous, attribute. Yet patchouli oil always had a sensual connotation, and since Indian girls ritually used to perfume their backs with patchouli oil to bewitch a lover, these molecules shine in front of a female back bearing their structural formulae in a lower backpiece fashion tattoo. The molecular design, synthesis and olfactory properties of these new odorants are discussed in the article by P. Kraft and A. Bruneau on p. 2257 ff.