94 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS showing no significant increase in yields compared with the latter (5). Therefore, in the present work, Woodward's method was chosen for the production of cis-diols (Scheme 1). On the other hand, the carbene/carbenoid reactions, especially with compounds having multiple bonds, have been an important research area for organic chemists in recent years (7-11). As it is known, reactions of diazo compounds, being mainly carbene precursors with various olefins, have been studied under photochemical, thermal, and catalytical conditions, yielding addition, insertion, and carbene dimerization products (12-13). The overall reaction is summarized in Scheme 2. RESULTS AND DISCUSSION In the present work, the above-mentioned reactions of three terpene compounds, terpinene, p-menth-l-ene, and •-pinene, which were raw materials isolated from several essential oils (18-22), were investigated (Scheme 3). One of the problems was the isolation in high purity of the expected products from the crude reaction mixture. As described in the Experimental section, only a few reactions, purification by crystalliza- tion could be achieved. The preparative thin-layer chromatography technique (p-TLC) was generally used to separate and purify the p.roducts for identification. The weight percentages of individual compounds relative to the total product weights (from GLC) are summarized in Table I. Hydroxylation of 'y-terpinene by the procedure described in the Experimental section gave only one kind of cis-diol 1, the structure of which was identified by its tH-NMR spectrum: Methyl protons resonated at 1.22 ppm, whereas the signal of the same protons appeared at 1.63 ppm in 'y-terpinene, proving that only the methyl-substituted double bond had reacted. The signal at 5.31 ppm could be attributed to the olefinic proton. These data showed the greater steric hindrance around the isopropyl-substituted double bond. Absorbdon of six methyl protons of the isopropyl group took place as a doublet centered at 1.0 ppm, and the proton attached to the hydroxylareal carbon ab- sorbed at 3.64 ppm as doublet-doublet and the other protons of the ring between 1.9-2.18 ppm, whereas the two OH protons resonated at 2.25 and 2.30 ppm, respec- tively. All rates of integrations were in good agreement with the suggested structure of 1. Expected product was also obtained from p-menth-l-ene by the same procedure. But the stereochemistry of compounds 1 and 4 could not be determined. Application of Scheme !

NEW ODOROUS TERPENES 95 R ,CHR'R" Catalytic ...: +N 2 - "(R') + ( ........ + , addition prod. insertion prds (allylic and others) R'R"CH--CHR'R" + R'R"C=CR'R" carbene dimers Scheme 2 Woodward's conditions to [3-pinene resulted in the formation of more than seven com- pounds via the cyclobutane ring opening, whereas the probable formation of the desired [3-pinene glycol could not be detected because of separation problems. As it is known, one of the characteristic reactions of cis-l,2-diols in slightly acidic medium is acetal formation with ketones. Therefore, the dimethylacetal derivatives of diols 1,4--and also 9, which was prepared--were synthesized, and the results are summarized in Scheme 4 and Table II. Compounds 10, 11, and 12 possessed odors which were different from and finer than those of the starting diols. The comparative analysis of the odor of the synthesized acetals of the investigated diols indicated the significant role of the gem-dialkyl group in the dioxolane ring in creating pleasant, floral-balsamic or floral-woody odors in the products. On the other hand, in the reaction of •/-terpinene with dimethyl-diazomalonate (dmdm), the GLC of the crude mixture showed a major component (71%). This compo- nent was extracted from p-TLC, and its 1H-NMR revealed two isomeric addition products (2 and 3) to the methyl-substituted double bond. Isomer ratio was 4: 1. Two different singlets were observed for the ester group of each isomer at 3.76, 3.63 for one, and 3.70, 3.59 for the other. Differences of the chemical shifts between individual singlets, approximately 22 Hz, were attributed to the effect of isopropyl-substituted double bond as proved by Dreiding models. In the reaction of p-menth-l-ene with dmdm, GLC revealed the presence of two main compounds (43.9 and 27.9%). Relatively pure samples of each component were ob- tained by p-TLC. The first one was a mixture of two isomeric addition compounds (5 and 6) having a ratio of 3:2 to each other from 1H-NMR data. The second compound was assigned the structure 7 as an allyl insertion product without specified stereochem- istry. In the last experiment, all possible products obtained in the reaction of dmdm with [3-pinene, excluding carben dimers and also ot-pinene, which could be isomerized from [3-pinene under present conditions, are illustrated in Scheme 5. Compound 8, which was detected as 89.1% by weight in the crude product, was extracted from p-TLC in a pure state. Its 1H-NMR spectrum showed clear signals at