Hydrocarbons, with Cyclo

To name a cycloalkane, prefix the name of the corresponding open-chain hydrocarbon with cyclo-, and name each substituent on the ring. If there is only one substituent, there is no need to give it a number. If there are two substituents, number the ring by beginning with the substituent of lower alphabetical order. If there are three or more substituents, number the ring so as to give them the lowest set of numbers, and then list the substituents in alphabetical order. 

To name a cycloalkane, prefix the name of the open-chain hydrocarbon with "cyclo."... 

Monocyclic Aliphatic Hydrocarbons. Monocyclic aliphatic hydrocarbons (with no side chains) are named by prefixing cyclo- to the name of the corresponding open-chain hydrocarbon having the same number of carbon atoms as the ring. Radicals are formed as with the alkanes, alkenes, and alkynes. Examples ... 

The chain and branched chain saturated hydrocarbons make up a family called the alkanes. Some saturated hydrocarbons with five carbon atoms are shown in Figure 18-11. The first example, containing no branches, is called normal-pentane or, briefly, n-pentane. The second example has a single branch at the end of the chain. Such a structural type is commonly identified by the prefix iso- . Hence this isomer is called /50-pentane. The third example in Figure 18-11 also contains five carbon atoms but it contains the distinctive feature of a cyclic carbon structure. Such a compound is identified by the prefix cyclo in its name—in the case shown, cyclopentane. 

A molybdenum-mediated oxidative coupling of aniline 1 with cyclohexene 2a provides carbazole 3. Alternatively, the same overall transformation of aniline 1 to carbazole 3 is achieved by iron-mediated oxidative coupling with cyclo-hexa-1,3-diene 2b or by palladium-catalyzed oxidative coupling with arenes 2c. The use of appropriately substituted anilines and unsaturated six-membered hydrocarbons opens up the way to highly convergent organometallic syntheses of carbazole alkaloids. 

Further experiments designed to elucidate acid-base relationships among weak acids have been carried out more recently by Streitwieser and his coworkers.50 They studied the equilibrium shown in Equation 3.44, with cyclo-hexylamine as solvent and lithium or cesium cyclohexylamide as base. Using spectrophotometric methods to evaluate the position of the equilibrium, they were able to find relative pKa values for a number of hydrocarbons in which the conjugate base is, in most cases, a conjugated aromatic anion. In order to attach... 

Cycloaddition reactions of benzyne with cyclic olejms, Benzyne reacts with cyclo-hexadiene to give, as the main products, hydrocarbons (l)-(4). The first (I) arises by 2 + 4 cycloaddition, (2) and (3) arise by ene cycloadditions, and (4) is a result of 2 + 2 cycloaddition. Addition of catalytic amounts of silver fluoroborate exerts a marked effect in this case (1) becomes almost the exclusive product. Silver ton, however. 

It can be seen from the graph that the equilibrium products at temperatures below 500°C are mainly alkanes (also known as paraffins or saturated hydrocarbons), with the equilibrium giving roughly a 2 1 ratio of isopentane to normal pentane. As the temperature is increased from 500°C to 600°C, there is increased formation of alkene compounds (also known as olefins). At 700°C, we see increased formation of cyclo-pentene and of dienes, and above 800°C dienes are the favored product. 

The solubility of individual hydrocarbons in pure water at 25 °C, as summarized by Tissot and Welte (1984) is given in Table 3.3. Table 3.3 indicates that there is a marked decrease in solubility with an increase in molecular weight (carbon number) for each class of hydrocarbons (alkanes, cyclo-alkanes, aromatics). It also shows that aromatics are more soluble than alkanes for a given carbon number. Polar heterocompounds (organic acids or alcohols) are more water soluble than the corresponding hydrocarbon with the same carbon number (Tissot and Welte, 1984). The hydrocarbon solubilities in water are influenced by temperature, salinity and pressure. 

The reaction can be extended to tricyclic hydrocarbons with a norbornene substructure, such as exo- and e Jo-tricyclo[5.2.1.0 - ]deca-3,8-diene (17). ° Side products are the [2 + 2] cyclo-... 

Similarly, benzylidene(pentacarbonyl) complexes of chromium and tungsten react with cyclo-pentadiene, by stereoselective transfer of the benzylidene moiety to one of the C-C double bonds of the diene, to form coordinated e do-6-phenylbicyclo[3.1.0]hex-2-ene 9 with the metal-ligand unit complexing from the exo side. This method was applied to several other dienes. Reaction with cyclohexa-1,3-diene gave the corresponding cndo-7-phenylbicyclo[4.1.0]hept-2-ene complex. The cyclopropane-containing ligands obtained in this way were liberated from the complex to form the free hydrocarbon system. 

There are two conventions used when counting electrons ionic and covalent (sometimes called the radical method). Consider the organic molecule cyclo-pentadiene, a planar five-sided hydrocarbon with the chemical formula CjHg. This is the precursor for the cyclopentadienyl ligand, also a planar molecule but has the chemical formula C5H5 and is given the abbreviation Cp. 

Radical Anions.—Mention has already been made of the reverse cycloaddition which occurs on reduction of (66) to (67) and which might be a concerted allowed process in the radical anion. Another example is reported. The radical anion (426) is made by reduction of the hydrocarbon with Na-K alloy at —110 °C. On warming to — 20°C it rearranges to the radical anion (427) of pleiadene—perhaps a [ 2 -I- 2J cyclo-reversion allowed because of the extra electron. ... 

Unsaturated hydrocarbons are formed by double and triple bonds between adjacent C-atoms. Hydrocarbons with double bonds derived from alkanes are called alkenes hydrocarbons with triple bonds derived from alkanes are called alkynes. The same holds for the cyclo-alkanes, where double bonds lead to c-alkenes. Benzene is the basic molecule for the class of aromatic compounds. Examples are... 

When the terpene a-fenchene (isopinene) is hydrated by means of acetic and sulphuric acids, it yields an isomer of fenchyl alcohol, which is known as isofenchyl alcohol (q.v.), and which on oxidation yields iso-fenchone, as fenchyl alcohol yields fenchone. The two ketones, fenchone and isofenchone, are sharply differentiated by isofenchone yielding iso-fenchocamphoric acid, Cj Hj O, on oxidation with potassium permanganate, which is not the case with fenchone. According to Aschan,i the hydrocarbon found in turpentine oil, and known as /9-pinolene (or cyclo-fenchene—as he now proposes to name it), when hydrated in the usual manner, yields both fenchyl and isofenchyl alcohols, which on oxidation yield the ketones fenchone and isofenchone. According to Aschan the relationships of these bodies are expressed by the following formulae —... 

Cyclopentane has the low chemical reactivity which is typical of saturated hydrocarbons, while 2-pentene is much more reactive. Similarly, ring structures containing double bonds, called cyclo-alkenes, can be shown to be isomeric with alkynes. 

The hydrogenation of simple alkenes, such as hexene, cyclohexene, cyclo-hexadiene and benzene, has been extensively studied using biphasic, alternative solvent protocols. These hydrocarbon substrates are more difficult to hydrogenate compared to substrates with electron withdrawing groups. Benzene and alkyl substituted aromatic compounds are considerably more difficult to hydrogenate... 

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