A Menthane

Chart 5. Names and Formulas of Type A (Menthane-Type) Monocyclic Terpene Hydrocarbons... 

Monocyclic Type A Menthane Type 5, p.19 Menthyl Menthylidene Menthenyl Menthylene Menthadienyl ... 

The acetylation of cis-cyclononene with acetyl chloride and aluminium chloride leads to a mixture, whose main component is a menthane derivative, chloro-l-acetyl-4-isopropylcyclohexane. ... 

Ansellone A is a new sesterterpene isolated from the couple Cadlina luteomarginata/Phorhas sp., collected near Ansell Point, British Columbia. This compound displays the new carbon skeleton of ansellane that formally associates a drimane and a menthane skeleton. Anselone A activates the cAMP signaling pathway (Daoust et al, 2010). 

Commercially, autoxidation is used in the production of a-cumyl hydroperoxide, tert-huty hydroperoxide, -diisopropylbenzene monohydroperoxide, -diisopropylbenzene dihydroperoxide, -menthane hydroperoxide, pinane hydroperoxide, and ethylbenzene hydroperoxide. 

A mixture of they -menthadienes can be hydrogenated to produce a mixture of i7j -y-menthane [6069-98-3] and /ra/ j -p-menthane [1678-82-6]. Oxidation to a mixture ofy)-menthane hydroperoxides gives a usehil polymerization initiator used in the mbber industry. 

Henderson and Sutherland have prepared a hydrocarbon synthetically which is possibly a modification of terpinene. They reduced thymo-hydroquinone, thus obtaining menthane-2-5-diol, which was heated for half an hour with twice its weight of sulphate of potash under a reflux condenser, and so yielded a terpene boiling at 179°, of specific gravity about 0 840 and refractive index 1-4779. 

The German ending -an should be translated -ane if it is the name of a hydrocarbon (or parent heterocyclic compound) which is fully saturated otherwise, -an. Examples methane, menthane, tolan, furan, pentosan. 

Scheme 9 Stereoselective synthesis of cw-p-menthane-l,7,8-triol (A) and cA-p-menth-8-ene-l,7-diol (B).

It should be noted that the preparation of complexes (RNC)AuCN can be carried out via very special routes. Thus AuCN reacts with Mel to give (MeNC)AuCN. This reaction involves an interesting A-alkylation of an Au(i)-bound cyanide group.219 Other (RNG)AuGN complexes were obtained from the reaction of K[AuC14] with the isocyanide in methanol. Examples are the compounds (L)Au2(CN)2 with L = l,8-diisocyano-/>-menthane or 2,5-diisocyano-2,5-dimethyl-hexane. The reactions proceed with a dealkylation of an isocyanide in the coordination sphere of a gold(m) center to produce free cyanide (Scheme 53).201... 

A 68% optical yield was obtained with the (- )-boman-2- ido-ol complex, and a 77% optical yield was obtained with a (/ )-(-)-p-menthan-3-ol complex. 

As an example What will be the product of heating l,2 I,4-di-epoxy-p-menthane,J. (Figure 9) with alumina in toluene A chemist would assume initial breaking of an epoxide-ring. But which one of the two Or will both break Furthermore, for each epoxide ring there are two possible choices of C-0 bonds. 

The two diastereomers of cis- and rmws-piperitone oxide are 1,2-epoxy-3-keto-p-menthanes, which have been found in various plant species. The most abundant natural sources of these compounds are plants belonging to the Lamiaceae family, especially Mentha and Calamintha In many publications, the authors gave no details on the diastereomeric composition of piperitone oxides, probably because of their very similar retention times on a non-polar column. 

Kopke X Mosandl A, Stereoisomeric flavor compounds. Part LIV 8-Mercapto-p-menthane-3-one -optically pure stereoisomers and chirospecific analysis, Z Lebensm Unters Forsch 194 372—376, 1992. 

Kopke X Schmarr HG, Mosandl A, Stereoisomeric flavour compounds. Part LVII Xhe stereoisomers of 3-oxo-p-menthane-8-thiol acetate, simultaneously stereoanalyzed with their corresponding thiols, FlavourFragr/7 205—211, 1992. 

A special case of asymmetric enantiomer-differentiating polymerization is the isoselective copolymerization of optically active 3-methyl-1-pentene with racemic 3,7-dimethyl-1-octene by TiCl4 and diisobutylzinc [Ciardelli et al., 1969]. The copolymer is optically active with respect to both comonomer units as the incorporated optically active 3-methyl-l-pentene directs the preferential entry of only one enantiomer of the racemic monomer. The directing effect of a chiral center in one monomer unit on the second monomer, referred to as asymmetric induction, is also observed in radical and ionic copolymerizations. The radical copolymerization of optically active a-methylbenzyl methacrylate with maleic anhydride yields a copolymer that is optically active even after hydrolytic cleavage of the optically active a-methylbenzyl group from the polymer [Kurokawa and Minoura, 1979]. Similar results were obtained in the copolymerizations of mono- and di-/-menthyl fumarate and (—)-3-(P-styryloxy)menthane with styrene [Kurokawa et al., 1982],... 

C H3 >=N-OH Na[BHJ/NiCl2 -6H20/C3OH - 30° 1 h Na[BH4]/Mo03/CH30H 0° - lh 3-Amino-4-methyl-1 -iso-propyl-cyclohexan (2-A mino-menthan) 6-Amino-l-methyl-4-iso-propyl-cyclohexen 90 90 5 5... 

Hydrogenation of a-terpineol yields />-menthan-8-ol. Terpineol is readily dehydrated by acids, yielding a mixture of unsaturated cyclic terpene hydrocarbons. Under mildly acidic conditions, terpin hydrate is formed. The most important... 

Cyclic terpene aldehydes occur in essential oils only in low concentration. These aldehydes are seldom used as single fragrance substances. A few of the cyclic terpene ketones are commercially important as fragrance and flavor substances, for example, menthone and carvone, which have the / -menthane skeleton, and the ionones, which have a (trimethylcyclohexenyl)alkenone skeleton. The ionones and... 

Of the few known terpene compounds that contain heteroatoms such as nitrogen or sulfur, the thiol 8-mercapto-p-menthan-3-one described below has qualitatively important applications as a fragrance and flavor substance. The second thiol, -p-menthene-8-thiol, is described because its odor threshold value is far lower than that of most other fragrance and flavor materials. 

Buchu leaf Agathosma betulina (Ber-gius) PUlans, A. crenulata (L.) PUlans trfl s-p-Menthane-8-thiol-3-one and its S-acetate (characteristic minor components), (+)-limonene (10)... 

Mercapto-p-menthan-3-one has been identified as a constituent of Buchu leaf oil [6] and is a very useful substance in black currant and tropical flavours. The reaction of pulegone with hydrogen sulfide in an alkaline medium results in 8-mercapto-p-menthan-3-one formation (Scheme 13.6). 

For instance, (-)-menthol (p-menthan-3-ol) is one of the most important flavouring agents and is the major compound in natural peppermint oil. The characteristic peppermint odour and the typical cooling effect is limited to (-)-men-thol. The other isomers do not show this refreshing effect. A racemic mixture of menthol holds an intermediate position the cooling effect is still perceptible. 

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