8-exo-formyl-2,6-exo-tricyclo(5.2.1.02,6)decane, method of preparing it and use of the same

PCT No. PCT/DE92/00307 Sec. 371 Date Dec. 11, 1992 Sec. 102(e) Date Dec. 11, 1992 PCT Filed Apr. 10, 1992 PCT Pub. No. WO92/18451 PCT Pub. Date Oct. 26, 1992.It was found that 8-exo-formyl-2,6-exo-tricyclo[5.2.1.02,6]decane having the constitution and stereochemistry of formula (I) possesses particularly useful olfactory properties which are clearly superior to those of the 8-endo-epimer and which already have an effect if compound (I) is enriched with mixtures of 8-exo- and 8-endo-epimers. Compound (I) can therefore be advantageously used, in pure or enriched form, as a scent or as a component of perfume compositions. To prepare an enriched epimer mixture, a mixture obtained in a known manner (U.S. Pat. No. 3,270,061) and having an exo/endo ratio of 1.45:1 is brought into equilibrium by base catalysis, preferably by the action of alkali hydroxides in alcoholic solution, to give an exo/endo ratio of 5.25:1. Alternatively, the enriched epimer mixture can be prepared starting from 8-formyl-2,6-exo-tricyclo[5.2.1.02,6]decene-3(4), catalytically hydrogenated for example with palladium coal and then optionally brought into equilibrium. Or 2,6-exo-tricyclo[5.2.1.02,6]decene-8 can be hydroformylated and also optionally brought into equilibrium. The pure compound (I) is prepared by reducing preferably a mixture of 8-exo- and 8-endo-epimers obtained in the manner known per se to a mixture of the corresponding alcohols, from which the 8-exo-configured methylol is isolated by chromatography or distillation and oxidized to obtain the aldehyde (compound I) again.