Ethylene series

As primary alcohols must contain the group (—CH2—OH), it is plain that the simplest primary alcohol of the ethylene hydrocarbons must be derived from the first hydrocarbon of this series which contains a methyl group. This will be the three carbon member, viz., propene, CH2 = CH—CH3. As ethene, CH2 = CH2, contains no such methyl group it can not yield a primary alcohol. 

The only hydroxyl substitution product of ethene which is possible, and the only one known, has the constitution represented by the above formula and is plainly a secondary alcohol as it contains the secondary group ( = CH—OH). It may be produced by the oxidation of ethyl ether by means of chromic acid, CrOa, ozone, or even by air when in the sunlight. 

This simplest primary alcohol of the ethylene series, and commonly known as allyl alcohol, is produced from glycerol (glycerin) by a reaction which will be discussed later. It is also produced by the destructive distillation of many organic substances, such as wood, and is therefore found as a constituent of crude wood alcohol. It is a colorless liquid with a strong odor and it boils at 96.6°. It mixes in all proportions with water. By the action of nascent hydrogen, Zn -f H2SO4, it is converted into the corresponding saturated alcohol  

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Analysis of the NMR chemical shifts of the triple bond carbon atoms of the substituted ynamines and comparison of these data with the corresponding values for compounds of the ethylene series suggest the presence of counterpolarization... 

Xthyl at, n. ethylate, -atber, m. ethyl ether, >azetat, n, ethyl acetate, -blau, n, ethyl blue. AthyleQi n, ethylene, -bindung, /, ethylene linkage, double bond, -jodid, n. ethylene iodide, -oryd, n. ethylene oxide, -reihe, /. ethylene series, -verbindung, /. ethylene compound,... 

BlaC33 Blair, C. M., Henze, H. R. The number of structurally isomeric hydrocarbons of the ethylene series. J. Amer. Chem. Soc. 55 (1933) 680-686. 

A hydrocarbon of the ethylene series, containing two double bonds in the molecule. Dipentamethylene Thiuram Tetrasulphide DPTT, accelerator. 

The dyad radicals of the ethylene series can be transformed into the monad radicals from which they are derived. If ethylene be digested with hydriodic acid for 50 hours at 100 C., it is transformed into ethylic iodide —... 

A complete analogy to the behavior of tneee cyclic compound can be found in the ethylenic series of hydrocarbon. Ethylene and propylene do not react with hydrobroiuic acid in glacial acetic acid,but c °=C . an<1 OhJ- ° C OH do1 thue the introduction of a methyl group ha lncreaaed the reactivity of the uneaturated compound,as it did tne reactivity of cyclopropane. Tne addition of hydrobromic acid givea mainly, the X of tne HX going to the moat... 

A series of nitrated and unsaturated hydrocarbons. TalS s3uS6 ITtOidCllid for nomenclature purposes is usually called the ethylene series because the first member is ethylene, C2H4 hence a molecular type CnH(2n-x) x02x rived. Other compds in the series are named after corresponding paraffins by adding to the stem ene or ylene such as 1-nitro propylene, CsHsNOj. Olefins with two conjugated double bonds are called dienes , such as butadiene. 

Because of this property of readily combining with other substances such as the halogens, ethylene and related hydrocarbons are said to be unsaturated. Ethylene is the first member of a homologous series of hydrocarbons, called the ethylene series. 

Isomers.—The number of possible isomers in the ethylene series is greater than in the saturated series as isomerism may be due not only to the character of the chain of carbons but also to the position of the... 

Just as ethylene, because of its unsaturation, readily takes up two mono-valent atoms, forming addition products, and thereby passing ovfer to the saturated series, so it has been found that acetylene, or ethine, readily takes up, by addition, either two or Jour mono-valent atoms. In the first case it passes to the more nearly saturated ethylene series and then to the fully saturated or methane series. This relationship may be shown by the following scheme ... 

Geraniol.— Alcohols derived from higher hydrocarbons of the ethylene series are known. The most important one is derived from a di-ene containing ten carbons and belongs to a class of compounds known as terpenes which will be considered later (Pt. II). It is called geraniol and has the following constitution. 

The aldehydes of the ethylene series which result from the alcohols by oxidation, and the acids which are the oxidation products of the aldehydes, both contain several important naturally occurring members. 

The aldehyde derived from the next higher hydrocarbon of the ethylene series, viz., the four carbon hydrocarbon, butene, is known as crotonic aldehyde because on oxidation it yields an acid known as crotonic acid. As there are two isomeric butenes due to the position of the double bond there will likewise be possible two isomeric aldehydes or butenals. 

This is the simplest case of the reaction but it has been mostly used in the synthesis of higher members of the unsaturated acid series, e.g., the nine carbon acid, nonylenic acid, which is prepared from the seven carbon aldehyde known as oenanthylic aldehyde, or oenanthol, obtained from castor oil. Even more important than its application in the synthesis of higher acids of the ethylene series is the use of the reaction in the synthesis of aromatic unsaturated cLcids derived from benzene and containing an unsaturated side chain (see cinnamic acid. Part II). The reaction is known as the Perkin Synthesis or as the Perkin-Fittig Synthesis from the men who suggested and explained it. 

The first member of the ethylene series of acidsj viz., propen-oic acid, or as it is commonly known, acrylic acid, is a sharp smelling liquid which boils at 140° and melts at 7 . It readily forms addition products. With hydrogen it yields propionic acid with hydrogen iodide, j3-iodo propionic acid and with water, jS-hydroxy propionic acid. This last acid, which we will consider later (p. 245), because of this relation to acrylic acid, is also known as hydraoylic acid. From these compounds just mentioned acrylic acid may be formed by the loss of the same elements. 

Synthesis from Propane.—The constitution of glycerol has been established by a series of reactions, as follows When secondary, or iso-propyl alcohol, propan-ol-2, is dehydrated an unsaturated compound is formed, viz., propene, the three carbon member of the ethylene series of hydrocarbons. When propene is treated with halogens, e.g.y chlorine, two atoms of the halogen add on directly and a saturated di-chlor compound results (see p. 158). 

For the preparation of halogen acids in which the substitution is in the beta or gammapositiOYi the reaction of the unsaturated acids of the ethylene series is usually employed. As ethylene by the addition of hydro-bromic acid yields brom ethane, so in like manner, unsaturated acids of the ethylene series take up halogen acids and pass to the mono-halo-genated saturated acid,... 

Glycol ethers as a class are not acutely toxic by the oral route. Inhalation exposure to high concentrations of compounds in the ethylene series can cause lethality. However, exposure to compounds in the propylene series was not lethal to rodents even at nearly saturated concentrations. 

Further, the halogen alkyls serve for the preparation of the unsaturated hydrocarbons of the ethylene series. 

ETHYLENE SERIES BY THE ELIMINATION OF WATER FROM AN ALCOHOL. COMBINATION OF THE HYDROCARBON WITH BROMINE... 

The hydrocarbons of the ethylene series may be prepared, in general, by abstracting water from the corresponding alcohol, e.g. ... 

In these cases it Is much more convenient to prepare an ester from the alcohol by the action of the chloride of a higher fatty add, and subjecting this to distillation by which it is decomposed into an hydrocarbon of the ethylene series and the free fatty add, e.g. r... 

In this reaction the tertiary chloride is formed as an intermediate product. The method is of importance for the preparation of di-add alcohols (glycols), especially for the a-glycols, in which the hydroxyl groups are dombined with the two adjacent carbon atoms. The dibromides corresponding to these alcohols are easily obtained by the addition of bromine to the hydrocarbons of the ethylene series. In this way glycol was first prepared by Wurtz.1... 

Cinnamic add, its homologues and analogues, behave on the one hand like adds, since they form salts, esters, chlorides, amides, etc. Further, they show the properties of the ethylene series in that they take up by addition the most various kinds of atoms and groups. By the action of nascent hydrogen two atoms of hydrogen are added to the molecule of cinnamic add with a change from double to single union ... 

The results for the complete series of acetylenic acids, except A3a, are given in Figure 5 by a plot of the area under the curve vs. triple bond position (see Figure 4 for some of the 7t-A curves). All of the compounds form more expanded films than the corresponding ethylenic acids consequently, the range of areas used for the comparisons in Figure 5 was chosen arbitrarily as 140 to 50 A2/molecule. Here, the pattern of change is quite different from that with the ethylenic series. The A2a and A4a are relatively condensed and similar to each other. 

To gain insight into the specific interactions between double bonds and water, compare the results from the acetylenic series, where triple bond—water interactions are more likely (5), with the results from the ethylenic series. The view that water—triple bond interactions are sig-... 

Dyad baayloue radicals of tlic ethylene series. .. Isomerism of ethylene and etbylidane compounds... 

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