The Importance of the 5-Alkyl Substituent for the Violet Smell of Ionones: Synthesis of Racemic 5-Demethyl-α-ionone

Abstract

The synthesis and the odor tonalities of racemic 5-demethyl--ionone are described. This synthetic ionone derivative did not show the typical floral-woody violet smell of -ionone, definitely proving the importance of a suitably sized and spatially oriented alkyl substituent at C(5) for stimulating olfactory receptors of ionones.

Bamford‐Stevens and Shapiro Reactions in Organic Synthesis

“…Finally, allylic oxidation of 129 with manganese oxide provided (+)‐γ‐coronal ( 130 ). While working on a similar type of compounds, Vidari group planned a synthesis of 5‐demethyl‐α‐ionone [44] . Compound 131 was prepared in nine steps starting from readily available methyl acetoacetate (Scheme 26).…”