174836-80-7

Upstream product

• 79-77-6 (E)-β-ionone 
• 68-12-2 N,N-dimethyl-formamide 
• 101315-22-4 5-(2',6',6'-trimethyl-1'-cyclohexen-1'-yl)-4-penten-2-yn-1-al 

Relevant academic research and scientific papers

Stereoselective functionalization at C-9 of retinal: Synthesis of 9- trans-19-nor-9-haloretinal analogs

Stereoselective functionalization at C-9 of retinal based on the use of the C4+X-unit is described. A sequential linkage of C4+X-units (X=Cl, Br, and I) with ylide 8 (C10) and phosphonate 12 (C5)selectively gave

9-Demethyl-9-haloretinals by Wadsworth-Emmons coupling - Easy preparation of pure (all-E), (9Z) and (11Z) isomers

5-(2′,6′,6′-Trimethyl-1′-cyclohexen-1′-yl) -4-penten-2-yn-1-al has been prepared in a one-pot process starting from β-ionone in almost quantitative yield. Using 1,4-nucleophilic addition reactions, the corresponding 9-Cl, 9-Br, 9-1 β-ionylideneacetaldehyde systems could be obtained in one step in quantitative yield as a mixture of (9Z) and (all-E) isomers. Even the corresponding fluoro derivative could be obtained in good yield as (9Z) and (all-E) isomers. In the case of a double bond having a halogen substituent, the IUPAC rules have the (E) nomenclature for a cis double bond and the (Z) for a trans double bond. Simple column chromatography gave the pure (9Z) and (all-E) form. Optimizing the Wadsworth-Emmons coupling gave the corresponding (all-E)- and (9Z)-retinonitriles in quantitative yield. Subsequent DIBAL-H reduction gave the corresponding retinals. For the preparation of the (UZ) isomers essential to vision, we found that Wadsworth-Emmons reactions with the diphenyl phosphonate group gave retinonitriles in quantitative yield, where the newly formed double bond is predominantly the (11Z) form (> 60%), together with the (9Z) isomer as minor component. The nitriles could be isolated in pure (9Z.11Z) and (9Z) forms by simple column chromatography. In the case of the (9Z,11Z)-9-demethyl-9-halo systems, a complication arose due to the unprecedented acid lability of these (9Z,11Z) aldehydes. By adjusting the DIBAL-H reduction workup procedure, these aldehydes are now available in pure form. We used this strategy to rationally synthesize (11Z)-retinal starting from β-cyclocitral as a first test for the generality of our new approach. β-Ionylideneacetaldehyde could be prepared in the (all-E) form in almost quantitative yield. Extending the conjugated chain of this molecule gave an almost quantitative yield of a mixture containing 80% (11Z)-retinal and 20% (all-E) as the minor component. Simple column chromatography gave pure (11Z)-retinal in 75% overall yield. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.

Synthesis of ionones and carvone analogues: Olfactory properties and preliminary toxicity assays

Vilsmeier reagents react with α/β-ionones and carvone to produce aldehydes 7-11 in a one-step procedure. The indene derivative 11, which came from the double iminoalkylation of carvone and ring closure with the elimination of dimethylamine, was practically odourless, while all the others had peculiar odours which were very different from the starting material. The cytotoxicity data of 9 and 10, which are the most promising potential perfume ingredients, are also reported.