6,6-DIMETHYLBICYCLO[3.1.0]HEXANE DERIVATIVES 111 secondary alcohols a moldy note (14) and a fruity-moldy note (20), and primary alcohol a leaf-green note (25). Based on its odorous properties, acetate 10 might be also included in this group. It exhibits very interesting and quite unusual sensory properties in comparison with other acetates. Esters 1 la,b, 12, 23a, and 24 form the second group of compounds. All of them exhibit medium-intensive fruity odors with various notes, and their characteristics also strongly depend on their chemical structure. It is worth noting that structurally related unsat- urated compound 23a and saturated ester 24 show a significant strawberry note in olfactory studies. The odors of a similar pair of compounds, 1 la,b and 12, differ in this respect, having bildberry and apple notes, respectively. Because of an interesting fruity flavor with a lemon note, aldehyde 13 might also be considered as a member of this group. Third, small group of compounds, namely ketones 15a and 22a, exhibits a floral-fruity flavor. Finally, nitriles 16a,b, 17, 18, and 21a,b might be considered as a separate group of flavorants because of their sharp penetrating odor with characteristic fruity-cuminic notes. Hydrogenation of the double bonds in described compounds causes a significant decrease in the intensity of olfactory properties. EXPERIMENTAL The course of all reactions, composition of products, and their purities were checked by means of thin-layer chromatography (TLC) and gas chromatography (GC). TLC was carried out on silica gel G (Merck). Chromatograms were developed with a mixture of hexane, ethyl ether, or acetone applied in various ratios and detected with 20% ethanolic H2SO 4 containing ca. 0.1% of p-anisaldehyde, followed by heating to 120øC. Column chromatography was performed on silica gel (Kiselgel 60, 230-400-mesh, Merck). Analytical GC was performed on a GCHF-18.3.4 and 18.3.6 (Chromatron) apparatus using the following: 15 % Carbowax 1000 on Chromosorb P 2% DEGS on Chromosorb G 20% PEGA on Chromosorb G or 10% XE-60 on Chromosorb G column length 1 or 3 m temperature 140-180øC. Melting points (uncorrected) were determinated on a Boetius apparatus. IR spectra were taken for liquid films or KBr pellets on a Perkin- Elmer 621 spectrophotometer. 1H NMR spectra were recorded for 10% CCI 4 or CDC13 solution on a 100-MHz Tesla BS 478 apparatus with HMDS as external standard. 2 OLFACTORY EVALUATION Odorous properties of the synthesized compounds were determined by Prof. J6zef G6ra strictly following the described procedure (12). INITIAL MATERIALS 20 (+)-3-Carene (Institute of Chemical Industry, Warsaw), b.p. 79øC/28 mmHg, n D 2 All analyses (IR, NMR, GC, elemental analyses) were performed in the Laboratory of Instrumental Analysis, Institute of Organic Chemistry, Biochemistry and Biotechnology, Technical University of Wrodaw.

112 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS 1.4758, •r• 2ø = + 14.0 ø, was transformed, via crystalline (-)-3,4-dibromocarane, to the trans-3-acetyl-6,6-dimethylbicyclo[3.1.O]hexane (6) according to the known procedure (6). GENERAL PROCEDURE FOR THE WADSWORTH-EMMONS REACTION Appropriate phosphonate W• or W 2 (0.09 mole) was added dropwise to a suspension of Nail (0.09 mole) in anhydrous DMF (50 ml), and the mixture was stirred vigorously until the evolution of hydrogen ceased. To the solution of sodium salt of phosphonate was added dropwise ketone or aidehyde (0.03 mole) in DMF (40 ml), and it was heated at 60-65øC approximately 2-3 h. When TLC control showed absence of starting ketone or aidehyde, the mixture was diluted with water (300 ml), extracted with diethyl ether, and dried over MgSO 4. The residue after removal of the solvent was purified by column chromatography and distilled in vacuo. GENERAL PROCEDURE FOR THE WITTIG REACTION WITH STABILIZED YLIDS The solution of aidehyde (0.03 mole) and acetonylidenophosphorane W 3 (0.06 mole) in anhydrous methylene chloride (200 ml) was refluxed to the moment when TLC control showed absence of substrate. Then methylene chloride was evaporated and hexane (100 ml) was added to the residue. Precipitated triphenylphosphine oxide was filtered off and washed several times with hexane. After evaporation of the solvent, the crude product was chromatographed on a column and distilled in vacuo. GENERAL PROCEDURE FOR THE GRIGNARD REACTION Aldehyde or ketone (0.03) in anhydrous diethyl ether (20 ml) was added dropwise to the Grignard reagent formed from appropriate alkyl halide (0.03 mole) and magnesium (0.03 mole) in anhydrous diethyl ether (60 ml). The mixture was stirred for 2-4 h. Then NH4C1 solution was added, and the product was extracted with diethyl ether. The etheral solution was washed with saturated NaCI solution and dried (MgSO4). The crude product was purified by column chromatography (if necessary) and distilled in vacuo. GENERAL PROCEDURE FOR OXIDATION WITH PCC Alcohol (0.03 mole) was added in one portion to a slurry of pyridinium chlorochromate (0.07 mole) and anhydrous sodium acetate (0.012 mole) in anhydrous methylene chlo- ride (100 ml). The mixture was stirred at room temperature for 3 h. Then the methylene chloride was evaporated and the residue was extracted with petroleum ether. The etheral solution was filtered through "Florisil" and evaporated. The crude aidehyde was chro- matographed on a column immediately before use (readily oxidizable in air). GENERAL PROCEDURE FOR REDUCTION WITH LiA1H 4 Carbonyl compound (ester, ketone 0.030 mole) in diethyl ether (35 ml) was added dropwise to the suspension of lithium aluminium hydride (0.050 mole) in diethyl ether