Synthesis 2012; 44(19): 2985-2998
DOI: 10.1055/s-0032-1317033
feature article
© Georg Thieme Verlag Stuttgart · New York

On the Crossroad of Dienone Musks and Cassyrane: Synthesis and Olfactory Properties of New High-Impact Orris Odorants

Philip Kraft*
Givaudan Schweiz AG, Fragrance Research, Überlandstrasse 138, 8600 Dübendorf, Switzerland, Fax: +41(44)8242926   Email: philip.kraft@givaudan.com
,
Joachim S. E. Ahlin
Givaudan Schweiz AG, Fragrance Research, Überlandstrasse 138, 8600 Dübendorf, Switzerland, Fax: +41(44)8242926   Email: philip.kraft@givaudan.com
,
Michelle Büchel
Givaudan Schweiz AG, Fragrance Research, Überlandstrasse 138, 8600 Dübendorf, Switzerland, Fax: +41(44)8242926   Email: philip.kraft@givaudan.com
,
Pascal Sutter
Givaudan Schweiz AG, Fragrance Research, Überlandstrasse 138, 8600 Dübendorf, Switzerland, Fax: +41(44)8242926   Email: philip.kraft@givaudan.com
› Author Affiliations
Further Information

Publication History

Received: 15 June 2012

Accepted after revision: 17 July 2012

Publication Date:
15 August 2012 (online)


Abstract

While investigating the effect of the Cassyrane (rac-3/4) substitution pattern on the odor of dienones, (3E,5E)-5-tert-butylocta­-3,5-dien-2-one (34) was discovered as an orris odorant with the lowest threshold reported so far in the ionone family (0.036 ng/L air). Derivatives 3537, which allowed some insight into the underlying structure–odor relationships, were synthesized by a sequence consisting of copper(I)-catalyzed Grignard reactions with acyl chlorides, cerium- and lanthanum-assisted Grignard reactions of the resulting products with the Grignard reagent 17, prepared from but-3-yn-2-ol, manganese(IV) oxide oxidation of the secondary hydroxy function, elimination of the tertiary hydroxy function via its mesylate, alanate reduction of the ynone moiety to the corresponding allylic alcohol, and concluding manganese(IV) oxide oxidation. Furthermore, the γ,δ-unsaturated 3841, and the fully hydrogenated analogues 4245 were synthesized, and evaluated for their olfactory properties.