Aromatic camphor

Properties Warm aromatic camphor-like odor, warm sweet si. burning flavor Toxicology No known toxicity Uses Natural flavoring agent in foods and pharmaceuticals stimulant carminative cosmetics ingred. 

At pressures of 13 GPa many carbonaceous materials decompose when heated and the carbon eventually turns into diamond. The molecular stmcture of the starting material strongly affects this process. Thus condensed aromatic molecules, such as naphthalene or anthracene, first form graphite even though diamond is the stable form. On the other hand, aUphatic substances such as camphor, paraffin wax, or polyethylene lose hydrogen and condense to diamond via soft, white, soHd intermediates with a rudimentary diamond stmcture (29). 

Comparison of Table 5.4 and 5.7 allows the prediction that aromatic oils will be plasticisers for natural rubber, that dibutyl phthalate will plasticise poly(methyl methacrylate), that tritolyl phosphate will plasticise nitrile rubbers, that dibenzyl ether will plasticise poly(vinylidene chloride) and that dimethyl phthalate will plasticise cellulose diacetate. These predictions are found to be correct. What is not predictable is that camphor should be an effective plasticiser for cellulose nitrate. It would seem that this crystalline material, which has to be dispersed into the polymer with the aid of liquids such as ethyl alcohol, is only compatible with the polymer because of some specific interaction between the carbonyl group present in the camphor with some group in the cellulose nitrate. 

Solids. —It may Idc a hydrocM bon (c .g., paraffin wa, naphthalene) highei alcohol eg., cetyl alcohol) aldehyde e.g., z5-hydroxybenzaldehyde) ketone and qiiinonc e.g., benzo-phenone, camphor) acid (higher fatty, e.g., palmitic acid or aromatic acid) ester (of glycerol, phenols or aromatic alcohols) phenol e.g., thymol),... 

Sulfinic esters, aromatic, by oxidation of disulfides in alcohols, 46, 64 Sulfonation ot d,l camphor to d,l-10-camphorsulfomc acid, 45,12 Sulfoxides, table of examples of preparation from sulfides with sodium metapenodate, 46,79 Sulfur dioxide, reaction with styrene phosphorus pentachlonde to give styrylphosphomc diclilonde, 46,... 

This reaction is equally amenable to enals with both aliphatic and aromatic P-substituents, althongh the formation of substitnted cyclohexanes (from analogous enals) proceeds with rednced enantioselectivity (Scheme 12.51) [92], You and co-workers have shown that the same reaction is also promoted by triazolinm salts derived from camphor in excellent enantioselectivity (95-99% ee) [93]). 

Although there are now several catalysts useful for hydrogenation of saturated carbonyl compounds to alcohols (see Section XII), an alternative approach has involved initial hydrosilylation (Chapter 9 in this volume) followed by acid hydrolysis [Eq. (41)]. The area first developed using principally the RhCl(PPh3)3 catalyst (207-210), and has since proved particularly useful in asymmetric syntheses (see Section III,A,4). Besides simple aliphatic and aromatic aldehydes and ketones, the ter-pene-ketones camphor and menthone were stereoselectively reduced to mainly the less stable alcohols e.g., camphor gave 9 (209). 

Tellurium Tetrahydrofuran Tetranitroaniline Tetranitromethane Thiocyanates Thionyl chloride Thiophene Thymol Halogens, metals Tetrahydridoaluminates, KOH, NaOH Reducing materials Aluminum, cotton, aromatic nitro compounds, hydrocarbons, cotton, toluene Chlorates, nitric acid, peroxides Ammonia, dimethylsulfoxide, linseed oil, quinoline, sodium Nitric acid Acetanilide, antipyrine, camphor, chlorohydrate, menthol, quinine sulfate, ure- thene... 

LiAlH(OBu )3 does not undergo disproportionation to the tetraalkoxy species. Reduction of the aromatic ketones studied involved either monomeric LAH or both this species and the monoalkoxy species, depending on the steric hindrance of the substrate. In a similar study of the reduction of camphor in THF (39), the kinetic results were also consistent with disproportionation of r-butoxy species (eqs. [6] and [7]), active reducing species being LAH and LiAl(OBu )H3. In the reduction of camphor with a series of reagents prepared by the reaction of LAH... 

Isoprene metabolism in plants is very complex. Plants can synthesize many types of aromatic substances and volatile oils from isoprenoids. Examples include menthol (1= 2 ), camphor (1 = 2), and citronellal (1 = 2). These Cio compounds are also called monoterpenes. Similarly, compounds consisting of three isoprene units (1 = 3) are termed sesquiterpenes, and the steroids (1 = 6) are called triterpenes. 

Monoterpenes, 10-carbon-containing terpenoids, are composed of two isoprene units, and found abundantly in plants, e.g. (+)-limonene from lemon oil, and (—)-linalool from rose oil. Many monoterpenes are the constituents of plant volatile oils or essential oils. These compounds are particularly important as flavouring agents in pharmaceutical, confectionery and perfume products. However, a number of monoterpenes show various types of bioactivity and are used in medicinal preparations. For example, camphor is used in liniments against rheumatic pain, menthol is used in ointments and liniments as a remedy against itching, bitter-orange peel is used as an aromatic bitter tonic and as a remedy for poor appetite and thymol and carvacrol are used in bactericidal preparations. 

T. Urbanski and Rabek-Gawronska [11] found that cyclonite dissolves in molten, highly-nitrated aromatic hydrocarbons, substituted urea derivatives, and camphor to form eutectics of the composition given in Table 18. It is almost insoluble in molten diphenylamine. 

Nitrocellulose powders gelatinized on the surface with centralite, camphor or nitro compounds are less hygroscopic since the layer of gel on the surface constitutes a non-hygroscopic coating which prevents the powder inside from attracting moisture. Nitrocellulose powders containing aromatic nitro compounds, e.g, dinitrotoluene (DNT) or dinitroxylene (DNX) are less hygroscopic. 

Reduction of tosyl- and trisylhydrazones.3 The reagent (1 equivalent) reduces tosylhydrazones of ketones to alkanes in yields of 60-85% (GLC). The reduction is Subject to sleric hindrance and so is not effective with the tosylhydrazone of camphor. Tosylhydrazones of aldehydes are reduced in moderate yield (about 50%). The reagent does not reduce tosylhydrazones of aromatic or a,/)-unsaturated aldehydes or ketones. 

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