Storks Total Synthesis of p-Vetivone

Patchouli Pogostemon cabliri) is a shrub which grows in Indonesia. Its leaves are harvested and allowed to ferment. This results in the formation of an intense and characteristic odour of a somewhat earthy nature. The oil is widely used in perfumery, particularly in after-shaves 

Another similarity with vetiver is the fact that the odour of Patchouli Oil owes little to the major component. The natural isomer, (—)-patchouli alcohol has some patchouli character whereas its unnatural enantiomer is odourless. However, this odour contribution is a small part of the total and most of the intense character of patchouli comes from minor components such as nor-patchoulenol (7.84) and nor-tetrapatchoulol (7.85). These are both degradation products, probably the result of the fermentation stage and explaining the necessity of including this in the production process. Nor-patchoulenol was identified and characterised by Paul Tesseire of the fragrance company Roure-Bertrand-Dupont and nor-tetrapatchoulol by Braja Mookherjee of International Flavours and Fragrances. 

The bicyclooctane core of the structure of patchouli alcohol suggests the Diels-Alder reaction as an approach to the synthesis and this was 

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