An expedient preparation of enantio‐enriched ambergris odorants starting from commercial ionone alpha

We report the enantioselective synthesis of the ambergris odorants (+)-(S)-γ-ionone, (+)-(S)-γ-dihydroionone, (−)-α-ambrinol, (+)-(S)-γ-coronal, (−)-(S)-γ-homocyclogeranyl chloride and (+)-(S)-γ-homocyclogeraniol. At first, the enantio-enriched (4R,6S)-4-acetoxy-γ-ionone was prepared starting from commercial racemic ionone alpha by means of a chemo-enzymatic process. This chiral building block was then converted into (S)-γ-dihydroionone which was used as the starting material for the synthesis of the aforementioned odorants. Copyright © 2012 John Wiley & Sons, Ltd.

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