SYNTHETIC PERFUME MATERIALS FROM PINENE 169 It had long been accepted that a synthesis of the current terpene alcohols could not be a prosperous venture since traditional isolating processes seemed firmly established and raw material abundant, at least under normal political conditions. In this extremely competitive field of staple perfumery, where an output of hundreds of tons has to be considered, not only chemical ingen- uity was needed, but also difficult engineering problems had to be tackled and substantial assets invested. That this problem has been successfully solved, and brought to a working industrial reality, is quite a major achieve- ment. The pinene products have already had a stabilising effect on the market. Even more drastic price reductions may be expected when production capacities will have been increased and are more in line with the demand. Alas, the perfumer very seldom conforms to that popular picture of a care- free artist dallying happily with Bulgarian Otto of Rose, Jasmin absolute, and similar exalted raw materials. Pencil and cost sheet are the inescapable companions of his smelling strip. But the synthesis of the terpene alcohols from pinerie has more than an economic aspect. The resulting alcohols have proved to be extremely pure, and therefore enabled the perfumer to make a new assessment of their odours. The rose alcohols, for instance, have revealed more distinctive individualities than would have been expected from the traditional isolates which, as we know, are generally mixtures of two or three alcohols. The perfumer is always on the look out for new ideas some new twist in a field where taste conventions, technical requirements, or just price considerations very often leave him little scope for fantasy. These new pinene synthetics will be found most helpful. It seems that not only can they replace the corresponding classical products isolated from natural oils, but they also offer new tonalities and therefore an opportunity for novelty. DISCUSSION DR. Y.-R. NAVES: The lecturer has good reason to emphasize the interest aroused in the products which can be made from/%pinerie--products which perfumers and chemists alike, are regarding as new raw materials. In fact we note that the lecturer agrees completely with the contention that these are new products, and that the perfumer is interested basically in odours and not in chemical substances as such. It is quite clear that the perfumer will appreciate the note of any of the products made from pinene as distinct from those made from alcohols from different sources. Whilst on this subject I should like to relate a story. Some thirty years. ago I prepared for Professors V. Grighand and J. Doeuvre, a sample of very highly purified laevo-citronellol, starting with Bulgarian Rose oil as raw

170 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS material. That product, and five commercial samples of citronellol emanat- ing from various reputable sources, were submitted under code numbers to six of the leading perfumers of the time, examining independently. The laevo-citronellol, made from the Bulgarian Rose oil, was unanimously considered to be the least acceptable for the purposes for which citronellol was used at the time. THE LECTURF•R: I very heartily agree with Dr. Naves about the interest of the pinene alcohols. As a perfumer I see their prime interest in their originality, in having, for instance, a really pure nerol or citronellol abso- lutely free from geraniol. But let us not forget that we can also mix these pure alcohols, and in some way, simulate a traditional product. I further agree with Dr. Naves that it is impossible to obtain complete .simulation of the traditional material, but I would underline that very often these products, a!one or blended, can in some ways afford substitutes for traditional isolates. In fact they are probably often used as such but again I would like to emphasize the aspect of originality, and their value as new products. Concerning Dr. Naves's story, I am just wondering how that highly purified product which was submitted thirty years ago, would stand up today to modern analysis by GLC, IR or NMR. DR. Y.-R. N^vEs: It may perhaps sound astonishing, but we have kept that sample for many years, and have subjected it to spectrophotometry, GLC and all the standard physical and chemical analyses. We have found it surprisingly pure, considering that it had been prepared at a time when such modern methods did not exist. I wish to re-emphasize that the reason why the citronellol obviously was not accepted at that time was because, being so pure, it represented a new product. It was rejected because it was something unknown, something new, and perhaps in a way it can be compared with the very pure product to which you referred, that has to be looked upon in an entirely new and constructive way. MR. A. H. Ru¾s: Hydroxycitronellal made from the citronellal fraction of Citronella oil Java contains isopulegol, and its hydrate as impurities. Should it be taken that your new hydration process is one that does not yield any isopulegol as a minor by-product ? TI•E LECTURER: Hydroxycitronellal, ex pinene, is chemically purer than the traditional material, which does not necessarily mean oilactively purer. One has to be extremely careful about the evaluation of the oilactive quality of a hydroxycitrone!lal. A certain standard odour is more or less generally accepted, but it is unknown whether this traditional odour is only due to hydroxycitronellal. Perhaps it is, but we just do not know.