Hydrocarbons, hydrocarbon carboxylic acids from methyl

The Logatchev hydrothermal vent fluids originate from the interaction between the underlying peridotite rocks and seawater. They have heen previously analyzed [4]. The H2 concentration is 12 mmol/wkg (data from 1996) and 19 mmol/wl (data from 2005) and the analyses made in 1996, 2004 and 2005 show a stable composition of the fluids. The analyses of the Ashadze vent fluids [5] also show a great amount of H2. Both these vent fluids, as those of the Rainbow site (36° l4 N on the MAR, 2,300 m) also contain significant amounts of C02, CH4, N2, CO. Their pH is acidic -3-4, the temperature of their fluids is 310-370 °C and the detected saturated hydrocarbons, carboxylic acids and methyl estets in the fluids have been proposed of either abiogenic origin or not [5,6]. 

Esters are named by replacing the ending -ic acid with the suffix -ate. The alcohol portion of the ester is named by replacing the -ane ending of the parent hydrocarbon name with the suffix -yl. The alkyl radical name of an ester is separated from the carboxylate name, eg, methyl formate for HCOOCH. Amides are named by changing the ending -oic acid to -amide for either systematic or common names, eg, hexanamide and acetamide. 

In fluorosulfonic acid the anodic oxidation of cyclohexane in the presence of different acids (RCO2H) leads to a single product with a rearranged carbon skeleton, a 1-acyl-2-methyl-1-cyclopentene (1) in 50 to 60% yield (Eq. 2) [7, 8]. Also other alkanes have been converted at a smooth platinum anode into the corresponding a,-unsaturated ketones in 42 to 71% yield (Table 1) [8, 9]. Product formation is proposed to occur by oxidation of the hydrocarbon to a carbocation (Eq. 1 and Scheme 1) that rearranges and gets deprotonated to an alkene, which subsequently reacts with an acylium cation from the carboxylic acid to afford the a-unsaturated ketone (1) (Eq. 2) [8-10]. In the absence of acetic acid, for example, in fluorosulfonic acid/sodium... 

This paper presents data on isolation and identification of the following types of geolipids from the Aleksinac oil shale, a Miocene lake sediment n-al-kanes, iso- and/or anteiso-alkanes, aliphatic iso-prenoid alkanes, polycyclic isoprenoid alkanes, aromatic hydrocarbons, saturated unbranched, aliphatic isoprenoid, hopanoic, and aromatic mono- and poly-carboxylic acids, fatty acid methyl esters, aliphatic y- and 6-lactones, cyclic y-lactones, aliphatic methyl- and isoprenoid ketones, and the triterpenoid ketone adiantone. Possible origin of the identified compound classes is discussed, particularly of those which had not been identified previously as geolipids. 

Fig. 4.31 Biodegradation pathways of hydrocarbon. Methyl-oxidation, by attack of the methyl group (-CH3) at the extremity of the hydrocarbon chain, results in formation of a carboxylic acid group (-COOH). P-oxidation indicates that oxidation occurs at the second carbon atom (counted from the end that bears the -COOH group, the a-carbon atom being immediately adjacent to the -COOH group). P-oxidation continues removing C2 units, and in effect unzips the hydrocarbon chain until it no longer exists.

Equations (10-4) and (10-4a) predict a linear dependence of logX or R i on n for samples of the general class X-i . Some experimental examples of this relationship are shown in Fig. 10-1. These include the elution of the unsubstituted aromatic hydrocarbons of carbon number n from alumina (a) and Florisil (f>), the equilibrium adsorption of the homologous carboxylic acids (C Fl2 nCOOH) on charcoalt (c), and the thin-layer separation of some methyl ester-substituted porphyrins (porph... 

---