Hydrocarbon acetylene

CONDENSATIONS WITH SODAMIDE IN LIQUID AMMONIA Acetylenic compounds are conveniently prepared with the aid of Uquid ammcx as a solvent. The preparation of a simple acetylenic hydrocarbon ( -butylacetylene or 1-hexyne) and also of phenylacetylene is described. Experimental details are also given for two acetylenic carbinols, viz., 1-ethynyl-eyciohoxanul and 4-pentyn-l-ol. It will be noted that the scale is somewhat laige smaller quantities can readily be prepared by obvious modifications of the directions. 

Ethylenic and acetylenic hydrocarbons combust spontaneously when they come into contact with nitric acid, within a millisecond. 

There are no liquid alkynes which can be conveniently prepared by the elementary student. Some of the properties of acetylenic hydrocarbons may be studied with the gas, acetylene. Although the latter may be prepared in moderate yield by the addition of ethylene dibromide to a boiling alcoholic solution of potassium hydroxide or of sodium ethoxide,... 

Fraction 2 and 3 (P.E.) provided, besides the sesquiterpene hydrocarbon mixture, a compound which on the basis of H NMR and MS spectral evidence was shown to be the acetylenic hydrocarbon pentayneene (9) C,Ht> previously isolated from A. artemisiifolia... 

Although lithium aluminium hydride does not reduce alkenes or acetylene hydrocarbons, it reduces allylic alcohols and their acetylenic counterparts. Thus cinnamic acid is reduced to dihydrocinnamyl alcohol. 

Very often the carbon framework of the future allene is already present in the substrate and often it is propargylic in nature. For example, base-catalyzed isomeriza-tions of acetylenic hydrocarbons - with the triple bond in a non-terminal (40) or terminal position - were often used to prepare allenic hydrocarbons in the early days of allene chemistry [8]. The disadvantage of this approach consists in the thermodynamic instability of the allenes produced if not prohibited for structural reasons, the isomerizations do not stop at the allene but proceed to the more stable conjugated diene stage. In practice, complex mixtures are often formed [9] (see also Chapter 1). 

Various intermolecular coupling reactions involving acetylene hydrocarbons have been reported to lead to vinylallenes. For example, 1-phenylpropyne (93), after activation with Hg(II) chloride, is first metalated by butyllithium treatment, then trans-metalated with zinc bromide and finally coupled with 1-iodo-l-phenylethene (94) in the presence of tetrakis(triphenylphosphine)palladium to provide the diphenylvinyl-allene 95 in moderate yield (Scheme 5.12) [31]. 

Explosive Properties and Decomposition of Copper Derivatives of Acetylene Hydrocarbons... 

Acetylenic Compounds are organic compounds contg at least one triple bond -O C-. They may be hydrocarbons, alcohols, acids, aldehydes, etc. The acetylenic hydrocarbons include, in addition to acetylene (qv), the higher members, such as allylene or propyne H,CC s CH, crotonylene or butyne -2 HjCC i C.CHj, valerylene or pentyne - 2 H, C2.C C.CH, etc... 

Expl properties and decomposition derivs of acetylene hydrocarbons 6 E439... 

Some of the many solvents that have been examined for certain hydrocarbon separations are listed in Table 13.8 part (c) for n-butane and butene-2 separations includes data showing that addition of some water to the solvent enhances the selectivity. The diolefins butadiene and isoprene are available commercially as byproducts of cracking operations and are mixed with other close-boiling saturated, olefinic and acetylenic hydrocarbons, often as many as 10-20 different ones. The most widely used extractive... 

KUCHEROV REACTION. The hydration of acetylenic hydrocarbons with dilute sulfuric acid in the presence of mercuric sulfate or boron trifluoride as catalyst. 

Reaction XXXIV. (c) Action of Carbon Dioxide on Sodium Acetylides in Dry Ether. (B., 12, 853 J. pr., [2], 27, 417 B., 33, 3586.)—This is an example of the great activating influence of a triple bond. When carbon dioxide is passed into a solution of the sodium derivative of an acetylenic hydrocarbon in dry ether, direct addition takes place to give the sodium salt of the next highest acetylenic carboxylic acid. For example, sodium allylene yields sodium tetrolate—... 

As described in Sec. 2.2.4.1, the acetylene hydrocarbons frequently have a bridge function [76,77a]. An example of their use is the synthesis of 7t-complexes of propargyl alcohol with copper(I) chloride (3.65) [77a] ... 

M2+02 (M = Mg, Ca, Sr) coordinatively unsaturated pairs are able to abstract a hydrogen ion from acetylenic hydrocarbons following the reaction path shown in Scheme 4 (—, surface plane R, alkyl group), with formation... 

The nitration of acetylene hydrocarbons proceeds in a more complex way than that of olefins. The first member of the series-acetylene-undergoes various reactions, for example, with nitric acid (see p. 82 and p. 599) Tolane (diphenylacety-lene) is nitrated with N204 to form dinitrostilbene. Two products are formed which are presumably a- and p- stereoisomers ... 

The acetylene hydrocarbons, CnH2n 2j polymerize without loss of hydrogen. 

All hydrocarbons take up nitrogen, forming probably cyclical polyamines methane and ethylene hydrocarbons seem to give tetramines and acetylene hydrocarbons, diamines. 

DegussaAG/LindeAG Acetylene Hydrocarbons (C, - Cs) Electric arc pyrolysis, hydrogen coproduction 1 1988... 

If this pretreatment applies to both the fresh C cut and the recycle of the effluent rich in acetylenic hydrocarbons produced by the subsequent separation stage, the buta-... 

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