Hydrocarbons, branched carboxylic acids

The formyl cation HCO+ (vco at 2110 cm ) is generated from CO under pressure in the presence of HF/SbFs. Concentrated sulfuric acid or the HCl/CuCl system, activates carbon monoxide toward the electrophilic attack on aromatic hydrocarbons to form aromatic aldehydes (Gatterman-Koch reaction). Branched carboxylic acids are obtained from alkenes and CO in the presence of concentrated sulfuric acid (Koch process) (equation 3). ... 

It is apparent that the Lewis-acid solvents (alcohols, carboxylic acids, and chlorinated hydrocarbons) provide much better selectivity for a given capacity than do the Lewis-base solvents (ketones, esters, amines, phosphoryls). Furthermore, branching of the solvent molecule is important, as shown In Fig. 15.2-7. The dashed lines relate selectivity so KD for normal carboxylic acids (solid points) and normal alcohols (open points). Branched carboxylic acids give substantially higher selectivities than do straight-chain acids for a given value of K0. The same is liue for alcohols. 

Fluorinated ether-containing dicarboxyhc acids have been prepared by direct fluorination of the corresponding hydrocarbon (17), photooxidation of tetrafluoroethylene, or by fluoride ion-cataly2ed reaction of a diacid fluoride such as oxalyl or tetrafluorosuccinyl fluorides with hexafluoropropylene oxide (46,47). Equation 8 shows the reaction of oxalyl fluoride with HEPO. A difunctional ether-containing acid fluoride derived from HEPO contains regular repeat units of perfluoroisopropoxy group and is terminated by two alpha-branched carboxylates. 

The Fischer-Tropsch synthesis, which may be broadly defined as the reductive polymerization of carbon monoxide, can be schematically represented as shown in Eq. (1). The CHO products in Eq. (1) are any organic molecules containing carbon, hydrogen, and oxygen which are stable under the reaction conditions employed in the synthesis. With most heterogeneous catalysts the primary products of the reaction are straight-chain alkanes, while the secondary products include branched-chain hydrocarbons, alkenes, alcohols, aldehydes, and carboxylic acids. The distribution of the various products depends on both the type of catalyst and the reaction conditions employed (4). 

Fatty acids Biochemicals that are composed of hydrocarbons attached to a terminal carboxylic acid group. They vary in the number of carbons and degree of multiple bonding and branching in the hydrocarbon. 

DICARBOXYLIC ACIDS. The diacids are characterized by two carboxylic acid groups attached to a linear or branched hydrocarbon chain. Aliphatic, linear dicurbuxylic acids of the general formula HOOCiCH ) COOH and branched dicarboxylic acids are tile subject of this article. The bifunciionaJily of the diacids makes them versatile materials. ideally suited for a variety of condensation polymerization reactions. Several diacids are commercially important chemicals that are produced in mullimillion-kg quantities und hud application in a myriad of uses. 

The major category of compounds identified in the virgin and recycled HDPE is comprised of aliphatic hydrocarbons, such as pentadecane, hexade-cane, 1-hexadenene, branched alkanes, branched alkenes and others all oligomers of HDPE. Certain differences between virgin and recycled plastics are, however, obvious, e.g. carboxylic acids such as hexadecanoic and oc-tadecanoic acid were found only in the recycled HDPE. Only two ketones were identified, 6-dodecanone and 2-nodadecanone, in the recycled HDPE the former was also present in the virgin material. 

Draw good diagrams of saturated hydrocarbons with seven carbon atoms having (a) linear, (b) branched, and (c) cyclic frameworks. Draw molecules based on each framework having both ketone and carboxylic acid functional groups. 

Since the early 1960s, superacids have been known to react with saturated hydrocarbons to yield carbocations, even at low temperature [41]. This discovery initiated extensive studies devoted to electrophilic reactions and conversions of saturated hydrocarbons. Thus, the use of superacidic activation of alkanes to their related carbocations allowed the preparation of alkanecarboxylic acids from alkanes themselves with CO. In this respect, Yoneda et al. have found that alkanes can be directly carboxylated with CO in an HF-SbFs superacid system [42]. Tertiary carbenium ions formed by protolysis of C-H bonds of branched alkanes in HF-SbFs undergo skeletal isomerization and disproportionation prior to reacting with CO in the same acid system to form carboxylic acids after hydrolysis (eq. (9)). 

Aromatic compounds > conjugated alkenes > alicyclic compounds > organic sulfides > unbranched hydrocarbons > mercaptans > ketones > amines > esters > ethers > carboxylic acids > branched hydrocarbons > alcohols... 

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