This involves the formation of a carbenium ion which is best described as a hybrid of the two structures shown. This then rearranges by migration of a bond, and in so doing forms a more stable tertiary carbenium ion. Elimination of a proton yields camphene.  [c.424]

When two or more atoms are common to more than one ring the compounds are called polycyclic ring systems They are classified as bicyclic tricyclic tetracyclic etc according to the minimum number of bond cleavages required to generate a noncyclic structure Bicyclobutane is the simplest bicyclic hydrocarbon its four carbons form 2 three membered rings that share a common side Camphene is a naturally occurring bicyclic hydrocarbon obtained from pine oil It is best regarded as a six membered ring (indicated by blue bonds m the structure shown here) m which two of the carbons (des ignated by asterisks) are bridged by a CH2 group  [c.130]

Fig. 2. Monoterpenes in hydrocarbon resins a-pinene [2437-95-8] (3), p-pinene [18172-67-3] (4), Hmonene [7705-14-8] (5), 3-carene [13466-76-9] (6), myrcene [123-35-3] (7), camphene [5794-03-6] (8), p-pheUandrene [555-10-2] (9), terpinolene [586-62-9] (10), and p-terpinene [99-86-5] (11). Fig. 2. Monoterpenes in hydrocarbon resins a-pinene [2437-95-8] (3), p-pinene [18172-67-3] (4), Hmonene [7705-14-8] (5), 3-carene [13466-76-9] (6), myrcene [123-35-3] (7), camphene [5794-03-6] (8), p-pheUandrene [555-10-2] (9), terpinolene [586-62-9] (10), and p-terpinene [99-86-5] (11).
Chlorinated Terpenes. A group of incompletely characterized insecticidal compounds has been produced by the chlorination of the naturally occurring terpenes. Toxaphene [8001-35-2] is prepared by the chlorination of the bicycHc terpene, camphene [79-92-5] to contain 67—69% chlorine and has the empirical formula C QH QClg. The technical product is a yellowish, semicrystalline gum (mp 65—90°C, d 1.64) and is a mixture of 175 polychloro  [c.279]

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.  [c.64]

Ordinary commercial camphor is (-i-)-cam phor, from the wood of the camphor tree. Cinnamonum camphora. Camphor is of great technical importance, being used in the manufacture of celluloid and explosives, and for medical purposes, /t is manufactured from pinene through bornyl chloride to camphene, which is either directly oxidized to camphor or is hydrated to isoborneol, which is then oxidized to camphor. A large number of camphor derivatives have been prepared, including halogen, nitro and hydroxy derivatives and sulphonic acids.  [c.78]

By oxidation with permanganate it forms pinonic acid, C,oH,<503, a monobasic acid derived from cyclobutane. With strong sulphuric acid it forms a mixture of limonene, dipentene, terpinolene, terpinene, camphene and p-cymene. Hydrogen chloride reacts with turpentine oil to give CioHijCl, bomyl chloride, artificial camphor .  [c.315]

Zemplen was also a formidable character, and working for him was quite an experience, not only in chemistry. He liked, for example, pubbing, and these events in neighborhood establishments could last for days. Certainly one s stamina and alcohol tolerance developed through these experiences. Recalling on occasion his Berlin days, Zemplen talked with great fondness of his lab mate, the Finnish chemist Komppa (of later camphene synthesis fame), who he credited not only with being a fine chemist but also with being the only one able to outlast him during such parties. In any case, none of this ever affected his university duties or his research.  [c.52]

Meerwein, while studying the Wagner rearrangement of camphene hydrochloride to isobornyl chloride with van Emster, found that the rate of the reaction increased with the dielectric constant of the solvent. Furthermore, he found that certain Lewis acid chlorides such as SbCh, SnCU, FeCb, AlCb, and SbCb (but not BCb or SiCU) as well as dry FICl, which promote the ionization of triphenylmethyl chloride by formation of carbocationic complexes, also considerably accelerated the rearrangement of camphene hydrochloride to isobornyl chloride. Meerwein concluded that the isomerization actually does not proceed by way of migration of the chlorine atom but by a rearrangement of a cationic intermediate. Hence, the modern concept of carbocationic intermediates was born. Meerwein s views were, however, greeted with much skepticism by his peers in Germany, discouraging him from following up on these studies (see Chapter 9).  [c.74]

CAMET catalyst 14C-Amino acids Camolar [609-78-9] Camoquin [6398-98-7] Camouflage Campesterol [474-62-4] Camphene [79-92-5]  [c.156]

Stereoselectivity. The addition of a boron—hydrogen bond across the double bond proceeds cleanly in a cis fashion leading to simple diastereoselection for suitably substituted double bonds. Double bonds ate approached by the hydroborating agent from the less sterically hindered face. The thermodynamically less stable addition products may result, as has been demonstrated for P-pinene and camphene (204,205). Botane discriminates well between faces differing significandy in steric hindrance. When the difference is small low selectivity results. Bulky, sterically demanding hydroborating agents show higher stereoselectivity. Functional groups may induence the stereochemistry of addition. For example, unsaturated bicychc amines by strong complexation of botane may have one face of the double bond mote hindered, and the addition is directed to the opposite side. In contrast, weaMy complexing groups like ethers may facihtate the addition from the same side.  [c.314]

The first practical synthetic organic insecticide was the potassium salt of 4,6-dinitro-2-methylphenol [534-51-1] developed in Germany in 1892 as a dormant spray for orchard pests. However, it was the discovery of the insecticidal properties of DDT in 1939 that began an era of chemical pest control resulting in the synthesis and evaluation of hundreds of thousands of synthetic organic chemicals as insecticides (4). Dichlorodiphenyltrichloroethane (DDT), with its efficient contact insecticidal action together with long residual persistence and relative safety to humans and domestic animals, largely replaced the arsenicals. Hundreds of new uses were developed and DDT production in the United States attained a maximum of 77,800 t in 1961. Massive use of other organochlorines, such as benzene hexachloride, chlorinated camphenes, chlordane, heptachlor, aldrin, dieldrin, and endrin followed, and by 1964 these chemicals represented 70% of the total (53,000 t) use of insecticides in agriculture together with organophosphates at 20% (10,600 t). However, as insecticide resistance supervened and concern over environmental pollution increased, the use of the organophosphates (introduced in 1948), and that of the carbamates (introduced in 1957) increased rapidly. By 1976, more than 200 chemical compounds were marketed as insecticides and the total appHcation to primary crops was 58,000 t. The organ ochl orines represented 29%, the organophosphates 49%, and the carbamates 19%. Cotton was the most heavily treated crop (49% of the total) followed by com, 25% and soybean, 6%. Increasing use of integrated pest management (IPM) practices and the introduction of the pyrethroids, which are effective at about one-tenth the appHcation rate of the older insecticides, resulted in decreased insecticide use and by 1982 the farm use on primary crops was estimated at 32,000 t, comprised of organ ochl orines, 6% organophosphates, 67% carbamates, 18% and pyrethroids, 4%. Com became the most heavily treated crop with 42% of the total, followed by cotton, 24%, and soybean, 16%.  [c.267]

Uses ndReactions. a-Pinene (8) is useful for synthesizing a wide variety of terpenoids. Hydration to pine oil, acid-catalyzed isomerization to camphene, thermal isomerization to ocimene and aHoocimene, and polymerization to terpene resins are some of its direct uses. Manufacture of linalool, nerol, and geraniol has become an economically important use of a-pinene.  [c.411]

Acid-cataly2ed isomerization of a-pinene is carried out by heating with catalysts or other activated clays. Camphene (13) and tricydene  [c.412]

Camphene Manufacture. Camphene (13) is produced by the reaction of a-pinene (8) with a Ti02 catalyst (80). Preparation of the catalyst has a great influence on the product composition and yield. Tricydene (14) is formed as a coproduct but it undergoes the same reactions as camphene thus the product is generally used as a mixture. They -menthadienes and dimers produced as by-products are easily removed by fractional distillation and the camphene has a melting poiat range of 36—52°C, depending on its purity. Camphene is shipped ia tank cars, deck tanks, and dmms.  [c.415]

See pages that mention the term Camphene : [c.64]    [c.77]    [c.77]    [c.387]    [c.401]    [c.424]    [c.242]    [c.74]    [c.138]    [c.130]    [c.130]    [c.423]    [c.424]    [c.424]    [c.429]    [c.429]    [c.430]    [c.431]    [c.431]    [c.432]    [c.434]    [c.1081]    [c.306]    [c.318]    [c.329]    [c.331]    [c.332]    [c.338]    [c.338]    [c.409]    [c.412]    [c.415]   
Carey organic chemistry (0) -- [ c.130 ]

Organic chemistry (0) -- [ c.130 ]

Advanced organic synthesis (1971) -- [ c.6 , c.161 ]

The chemistry of essential oils and artificial perfumes Volume 2 (1922) -- [ c.50 ]