Camphor smell

Often, the correlation is not good, and we need to search for the hidden variable that we have not yet discovered. But when we find a good correlation, it could prove useful in the reverse search for other untried compounds that may have higher or lower camphor smell, even if we do not understand the mechanism of how it works. There is always the hope that, if we know which parameters are important to smell, we may generate one or more hypotheses on the nature of camphor smell this would be followed by predictions and experiments that could lead us to future understanding. 

Bornane monoterpenes are exemplified by camphene (2,2-dimethyl-3-methylene-bicyclo[2,2,1]heptane), a structure in which two fused cyclopentane rings share three Cs. We can simply represent the camphene skeleton as a cyclohexane with a methylene (—CH2—) cross-link (G6(-CH2—)). The keto derivative camphor (camphor smell), the ether eucalyptol (eucalyptus smell) and the simple bornene a-pinene (pine smell) are familiar examples. 

One important point on smell is that just as with taste molecules of different structures, often totally different molecules, have the same or different smell. An example of rose odor in reference (1.) sites the work of Wright (12) where rosetone, phenylethanol, geraniol and pelargol are compounds with very different structures but the same smell. He also attributes camphor smell to camphor, chloroethane and ethyl-tert-butyl ether (12). Other research of this type would be odorant molecules of similar structure with a different olfactory response. In 1929 Braun (13) studied a series of ketones where the carbonyl moved from carbon two through carbon six of an eleven carbon ketone. 

Borneol and isoboineol are respectively the endo and exo forms of the alcohol. Borneol can be prepared by reduction of camphor inactive borneol is also obtained by the acid hydration of pinene or camphene. Borneol has a smell like camphor. The m.p. of the optically active forms is 208-5 C but the racemic form has m.p. 210-5 C. Oxidized to camphor, dehydrated to camphene. 

Epicamphor is prepared from methyl-( + )-bornylene-3-carboxylate, and does not occur naturally. The smell of epicamphor differs slightly from that of camphor. 

Hexachloroethane vapors smell like camphor. You can begin to smell hexachloroethane in air when there are 150 parts present in a billion parts of air (ppb). You can smell it in water at 10 ppb. Neither a description of the taste nor the amount of hexachloroethane that gives a taste to water were found. 

N-Etbyl-2,6-dimetbylaniline (Athyl-vic-m-xylidin In Ger), mw 149-24, bp 217—18% oil smelling of camphor. It is prepd by reacting vic-m-xylidine with EtBr and NaOH at 180° N-Elby 1-2,5-dime tbylaniline (Xthyl-p-xylidin in Ger), mw 149.24, bp 222-23° (748 tort), oil smelling of naphthalene, it is prepd by hydrolysis of the corresponding benzene sulfonate with coned HCl at 150°... 

Why does a freshly cut Ping-Pong ball smell of camphor ... 

NAPHTHALENE. [CAS 91-20-3], Naphdialene C10H8, is a white solid with a strong smell is also called mothballs, moth flakes, white tar, and tar camphor. Naphthalene is a natural component of fossil fuels such as petroleum and coal it is also formed when natural products such as wood or tobacco are burned. 

Camphor is solid. We can smell camphor because there is some camphor vapour present above solid camphor. This is an example of a gas above a solid. 

The cellulose nitrate plastics were adaptable, easy to work, and quite durable, but had the disadvantages of being plasticized with camphor and flammability (they burnt, in fact, quite violently). At one time the smell of camphor was thought pleasant (even therapeutic) but instances have been cited of harm to children attributed to inhaling this vapour. So, while the acetates were not quite so attractive in terms of ease of fabrication it was inevitable eventually that the so-called safety plastic would supersede its forerunner. Among other uses it was stitched into motor car tonneau covers as flexible glazing, and thicker transparent sheet was cut and formed into cockpit canopies for aircraft [though by that time the material preferred for this purpose was poly(methyl methacrylate)]. Later on, in their turn, sheets made from cellulose acetate butyrate and propionate took over some of the uses of earlier commercial materials. 

Terpenes were originally named after turpentine, the volatile oil from pine trees used in oil painting, whose major constituent is a-pinene. The term was rather vaguely used for all the volatile oily compounds, insoluble in water and usually with resiny smells from plants. The oils distilled from plants, which often contain perfumery or flavouring materials, are called essential oils and these too contain terpenes. Examples include camphor from the camphor tree, used to preserve clothes from moths, humulene from hops, which helps to give beer its flavour, and phytol, found in many plants. 

I write what he dictates, but I am not happy with the idea of phlogiston. I think that the results of our experiment support Stahl s theory to an extent but don t prove it. I wish we could catch the air inside the glass and do more experiments to see how it really differs in quality from what Stahl would call the dephlogisticated air around us, but I say nothing of this to my father. I do as he says, and after a while I feel peaceful again. I love the flow of ink from my pen, the smells of sulfur and camphor, dusty wig and tobacco, and the satisfaction of watching an experiment go as predicted. Out of the comer of my eye, I notice that my father s hands are trembling more than ever and that after a little while his knees sag and he perches on a stool. 

Compound 117 had a camphoric odor with additional green notes while its carbon analogue smells like mint and even turpentine. The sila- S-ionone 118 and /)-ionone have similarly strong violet and freesia odors. 

Direct Tests on Stomach Contents. Odour, colour, and pH. Characteristic smells may indicate the presence of substances such as camphor, cresol, cyanide, etiianol and otiier organic solvents, ethchlorvynol, methyl salicyl-ate, paraldehyde, and phenelzine. A high pH may indicate ingestion of alkali. Undegraded tablets or capsules should be retrieved and examined separately. A green or blue colour suggests the presence of iron salts. 2.Salicylates—Trinder s test To 2ml of tiie sample add 2ml of O.IM hydrochloric acid, boil for 10 minutes, filter if necessary, neutralise the filtrate with... 

There are many species of Bitumen Liquid, like oil in appearance, and petroleum. There is the odorous liquid Bitumen of Saxony, cleansing, and with a smell of natural camphor. There is the gross, black Bitumen, which takes its name from the Lake of Sodom with this the Moors embalm dead bodies. There is the black, gross Palestine Bitumen, which is dug up like coal from the earth. 

Unless stored in perfect conditions, an object made of celluloid can degrade, giving off a smell of camphor (which smells like moth balls), and turning sticky or powdery (Fig. 13.3). 

Plant parts Fruits. Can be mixed up with the toxic fruits of Illicium anisatum L. (shikimi fruits), which do, however, not smell like anise but camphorous and bitter. 

According to stereochemical theory, the mechanism of smell depends on the binding of an odor molecule to a specific receptor site, which resembles the lock-and-key mechanism of enzyme catalysis. If two substances fit the same receptor, they should have the same odor, even if they differ in chemical composition. There are seven different kinds of olfactory receptors, each of which will accept a molecule that has the appropriate geometry. For putrid molecules such as hydrogen sulfide (H2S), however, polarity is more important than shape in linking up with a receptor. In addition, if different portions of a molecule fit different receptors, the molecule should have a mixed odor. For example, portions of benzaldehyde fit the camphor-like, floral, and peppermint receptors we recognize the resulting aroma as almond. 

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