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The synthesis of the title compound is described. Starting with the α-alkylation ofhomo-norcamphor followed by aWittig reaction, aTebbe transformation, and aDIBAH ester-reduction as the most important reactions of a 5 step sequence, (Z)-homo-β-santalol was obtained, which exhibits the typical precious sandalwood odour. The moderate increase of the volume of the bulky group obviously does not alter the odour quality “sandalwood” of this new β-santalol analogue.

The synthesis of the title compounds is described. Guided by theoretical considerations and molecular modeling studies, the influence of the bulky group opposite to the osmophorically important primary hydroxyl function on the odour impression is determined. The organoleptic evaluation proved the predicted sandal like odour of the (Z)-isomer and its also predicted absence with (E)-isomer. A moderate increase of the volume of the bulky group shows no influence on the sandalwood odour of the new analogue.

Guided by molecular modeling studies, the synthesis of the title compound is described. The organoleptic evaluation proved the predicted real sandal like odour of (Z)-dehydro-homo-β-santalol.

The ozonolysis ofendo-2-acetyl-3,3-dimethylbicyclo[2.2.1]hept-5-ene (endo-1) and itsexo-epimer (exo-1) is described. The reaction products, after reductive work up as well as after oxidative work up, are characterized. The first procedure furnished the corresponding cyclopentane derivatives in good yield, namely 1,1-dimethyl-2-(1-hydroxyethyl)-3,5-bis-hydroxymethyl cyclopentane (2) as a cristalline compound fromendo-1, the epimeric10 as an oil fromexo-1. The oxidative work up furnished in both cases via keto-enol-tautomerism the same acid, 4-acetyl-5,5-dimethyl-1,3-cyclopentane dicarboxylic acid, characterized as its methyl ester. Selective oxidation of the secondary hydroxyl group in2 lead to the novel, tricyclic, even acid stable ketal17, with very interesting olfactory properties.

In continuation of studying structure/odour relationships of odourous compounds, the tricyclic patchouli-system is degraded to bicyclic structures by cutting the C6-C7 bond (8 and9) or by omitting the methylene group of C11 (12). The olfactory properties are studied and described by using the key odour descriptors — woody, earthy, and camphoraceous.

The separation of a complex mixture of a fragrance material into its isomers is described. Instead of an odour of sandalwood the mixture exhibits mainly a mushroom odour but also the pure isomers show other organoleptic qualities. The structure of two isomers could be ascertained mainly by13C- and1H-NMR-measurements, for two isomers a structure proposal is given.

Some derivatives of 5,6-dihydro-2H-pyran-3-carboxaldehyde (7) and of its oxidation product 5,6-dihydro-2H-pyran-3-carboxylic acid (8) have been prepared. The aldehyde derivatives as well as the amides and esters of8 have been tested in an insecticidal/fungicidal/acaricidal screening programme. The methylester35 shows a distinct knock down effect against the fruit flyDrosophila melanogaster.

The bicyclo[2.2.1]- and [2.2.2]-systems are part of numerous biological active substances. Continuing our syntheses in the isocamphane series the homologous isocamphanes of mecamylamine (1 a) and of the fungicidal bicyclic compound2 were synthesized. Furthermore the syntheses ofE-homoisosantalene (15) andE,E-homoisosantalol (16) are described.

The diketone1 undergoes base induced ring opening to the δ-ketoacid2 a. Subsequent stereoselective reduction of the carbonyl-group affords the corresponding hydroxyacid4 a and condensation leads to the bicyclic lactone5 which can be reduced to the title compound6. Similar O-cage-compounds are known for antiviral activity. The olfactory properties of the compounds5 and6 are described.

Some esters of isocamphenilanic acid (4) have been prepared and tested for their fungicidal and insecticidal activity. Esters of various acids with isocamphanyl ethylalcohol (5) have also been synthesized and included in the fungicidal/acaricidal/insecticidal screening programme. All esters bear a geminal dimethyl group at C-3 of the bicyclus which is important because of its shielding effect.

To study the structure/odour relationships of β-santalol analogues two homologous β-santalol derivatives5 and6 were synthesized. The key steps thereby were the α-alkylation of the bicyclic starting ketones8 and14 accomplished by using more drastic conditions as usual. The odours of5 and6 are described in detail.

Syntheses of the title compounds are described and their olfactive properties discussed. Bishomocamphenilone (2) has been prepared by a Diels-Alder reaction of acrylonitril and cycloheptadiene-1,3 via the bicyclonitril5 which upon geminal chlorination and alkaline oxidation furnished the bishomonorbornanone9 which then could be transformed into2 by twofold methylation.14 has been prepared by action ofMeLi upon2 and bishomocamphene by dehydration of14. Hydroboration of this olefine3 yielded the alcohol15, which could be oxidized to the corresponding aldehyde13 and bishomocamphenilanic acid (4). The configurations of all new compounds has been ascertained.

Syntheses of the title compound and of some of its derivatives are described. Homocamphenilanic acid could not be obtained by aDiels-Alder reaction of cyclohexadiene with an appropriate dienophile but is easily accessible via homocamphene by hydroboration of this homoterpene and subsequent oxidation of the reaction product.

Most vegetables contain different amounts of iso- and anteiso-fatty acids, α-methylated acids were detected too, but so far only in tomatoes. Vegetables contain a great variaty of hydroxylated acids, especially α-hydroxy acids. The detected iso- and anteiso-fatty acids and alcohols may be the source of similar branched chain acids identified earlier in rather high amounts in skin and hairs of man and animals. They might also be the source of branched aldehyde components in plasmologens.

The synthesis of racemic 4,11,11-trimethyltricyclo[5.3.1.05,8]undec-4-en-7-ol (4), a new analogue of norpatchoulenol is described. ByDiels-Alder reaction of 6,6-dimethylcyclohexadienone (3) with methylvinyl ketone followed by hydrogenation and epimerization thesyn-diketone7 was obtained which then has been subjected to aGrignard reaction with vinyl magnesium bromide. After protection of the hydroxyl group of the resulting ketol8 the ketoether9 could be cyclisized to4 by means of a lithium suspension in refluxingTHF.4 shows a weak, characteristic odour of patchouli.