Alcohol from sources other than

Alternative fuels fall into two general categories. The first class consists of fuels that are made from sources other than cmde oil but that have properties the same as or similar to conventional motor fuels. In this category are fuels made from coal and shale (see Fuels, synthetic). In the second category are fuels that are different from gasoline and diesel fuel and which require redesigned or modified engines. These include methanol (see Alcohol fuels), compressed natural gas (CNG), and Hquefted petroleum gas (LPG). 

The wide distribution of PKSs in the microbial world and the extreme chemical diversity of their products do in fact result from a varied use of the well-known catalytic domains described above for the canonical PKS systems. Taking a theoretic view of polyketide diversity, Gonzalez-Lergier et al. (41) have suggested that even if the starter and extender units are fixed, over 100,000 linear heptaketide structures are possible using only the 5 common reductive outcomes at the P-carbon position (ketone, (R- or S-) alcohol, trans-double bond, or alkane). Recently, it has become apparent that even this does not represent the upper limit for polyketide diversification. To create chemical functionalities beyond those mentioned above, nature has recruited some enzymes from sources other than fatty acid synthesis (the mevalonate pathway in primary metabolism is one example) not typically thought of as type I PKS domains. Next, we explore the ways PKS-containing systems have modified these domains for the catalysis of some unique chemistries observed in natural products. 

A complement to hydrogenation that has practical uses is "transfer hydrogenation." In transfer hydrogenation, the hydrogen equivalent is derived from sources other than Hj. These catalysts transfer hydrogen from alcohols, formic acid, metal hydrides (such as NaBHJ, or the hydrolysis of coordinated CO (via the water gas shift process discussed... 

Methanol and a number of other alcohols and ethers are considered high-octane enhancers of gasoline. They can be produced from various hydrocarbon sources other than petroleum and may also offer environmental advantages insofar as the use of oxygenates would presumably suppress the release of vehicle pollutants into the air. 

Natural source descriptions are used to describe alkyl species that are derived from a particular animal or vegetable source, i.e., coco alcohols, soya fatty acids, and tallow amines. The EPA and CAS currently regard source-derived registrations as the most specific, very narrowly based, description of fatty acid products. Source-based descriptions are interpreted as substances which are solely derived from the named source. A more chemically detailed description is not ordinarily interchangeable with a source-derived description even if the chemically detailed description is totally accurate because sources other than that named could be used. However, a chemically detailed description could be changed to a source-derived description if the substance was derived from the source described. 

Just as in the case of aromatic compounds isoparaffins can be alkylated with sources of alkyl groups other than olefins. Alkyl halides, alcohols, ethers, mercaptans, sulfides, etc., can be used. When olefins are used some alkyl fluorides from a combination of olefin and hydrogen fluoride are always formed. The quantity of this in the product can be greatly reduced by providing conditions under which the alkyl fluoride is used in alkylation. The apparent paradox is provided, in that the fluoride content of the product is lessened by further treatment with hydrogen fluoride. A more thorough treatment of the details of the alkylation of isoparaffins with olefins is found elsewhere in this volume. 

A systematic study of the reductive alkylation of acetophenones revealed that the desired transformation (Scheme 30) required a careful selection of reagents and conditions. The best results were obtained from reduction by potassium in ammonia at -78 °C, with t-butyl alcohol as the proton source. Exchange of the potassium counterion of the enolate (152 M = K) for lithium then ensured regioselective alkylation at C-1 to give (153) in 80-90% yields (Scheme 30). Metals other than potassium as the reductant led to undesirable side reactions with the carbonyl group, which included simple reduction to the methylcar-binol and ethylbenzene (lithium or sodium), while the absence of a proton source or presence of a strong... 

Other selected examples are summarized in Table 1-10. In addition to aldehydes, both cyclic and acyclic ketones can be reduced equally well. jf c-Phenethyl alcohol (59, R=Ph) as hydride source works more effectively than i-PrOH. Based on this finding, the asymmetric MPV reduction of unsymmetrical ketones [63] with chiral alcohol in the presence of catalyst 58 was examined. Treatment of 2-chloroacetophenone (60) with optically pure (f )-(-t-)-sec-phenethyl alcohol (1 equiv) under the influence of catalytic 58 afforded (5)-(-t)-2-chloro-1 -phenyletha-nol (61) with moderate asymmetric induction (82%, 54% ee). Switching chiral alcohols from (/ )-(-f)-sec-phenethyl alcohol to (/ )-(-i-)-a-methyl-2-naphthalene-methanol and (f )-(-H)- fcc-o-bromophenethyl alcohol further enhanced the optical yields of 61 in 70 and 82% ee, respectively [62]. 

Catalyzed hydrogen transfer from a hydrogen donor (other than H2) to an unsaturated organic substrate is attractive industrially because of safety, engineering, and economic concerns. The use of alcohols as both cheap and plentiful hydrogen sources under relatively mild conditions has been widely reported, although other donors, such as formic acid, amines, cyclic ethers. 

Ethyl alcohol commonly occurs in one of three general forms. Absolute alcohol is ethyl alcohol that contains less than 1 percent impurities, such as water. Absolute alcohol is very difficult to make because ethyl alcohol will absorb water from the atmosphere or any other source that is available. The ethyl alcohol used in fuels and almost all industrial operations is a mixture of 95 percent ethyl alcohol and 5 percent water. Both absolute and 95 percent ethyl alcohol are extremely toxic. Ingestion of even very small amounts of either liquid has serious health effects that may include death. 

A particular acetylene can afford various products depending on the conditions. Diphenylacetylene in the presence of water, acetic acid, and alcohol, affords 38% traw -PhCH C(Ph)COOH and 10% of its ethyl ester (5). Tolane can also be carbonylated in alkaline solutions (8) where a complex carbonylate, possibly Ni3(CO)8 , is the source of carbon monoxide. Under these conditions tetraphenylbutadiene is isolated in addition to ra x-PhCH=C(Ph)COOH. The carbonylation of diphenylacetylene in dioxane in the presence of absolute alcohol and concentrated hydrochloric acid affords l,2,3,4-tetraphenyl-2-cyclopentene-l-one (9). Finally, in inert solvents diphenylacetylene reacts with nickel carbonyl, forming both tetraphenylcyclopentadienone and a n complex, bis(tetra-phenylcyclopentadienone)-nickel (10) (see Section VI). Since cyclopenta-dienones are often formed by treating alkynes with metal carbonyls other than nickel carbonyl the carbonylation reaction with this carbonyl must be closely related. The only difference apparently arises from the presence of... 

In the first process above, the identity of HA+ (the proton source) is most likely a protonated alcohol, which received its proton from the acid catalyst. Similarly, in the second process above, the identity of HA is most likely a protonated amine (called an ammonium ion), which received its proton from the acid catalyst Other than that small difference (and the difference described in the note beneath the second process), both mechanisms are the same. Both involve a proton transfer and a nucleophilic attack, followed hy more proton transfer steps, and then loss of water. But the conclusions of these meehanisms truly depart fiom one another. Let s try to understand why. 

The spectmm of oxo products ia Japan is far less diverse. Nearly 75% of Japan s total oxo capacity of 733,000 t is dedicated to the hydroformylation of propylene. 2-EH derived from -butyraldehyde is by far the dominant product. Other products iaclude linear alcohols and higher branched alcohols. Additionally, Japan is the world s principal source of branched heptyl alcohol. The three ptincipal Japanese oxo producers having slightly more than 70% of Japan s total oxo capacity are Mitsubishi Kasei, Kyowa Yuka, and Japan Oxocol. 

Uses ndReactions. Some of the principal uses for P-pinene are for manufacturing terpene resins and for thermal isomerization (pyrolysis) to myrcene. The resins are made by Lewis acid (usuaUy AlCl ) polymerization of P-pinene, either as a homopolymer or as a copolymer with other terpenes such as limonene. P-Pinene polymerizes much easier than a-pinene and the resins are usehil in pressure-sensitive adhesives, hot-melt adhesives and coatings, and elastomeric sealants. One of the first syntheses of a new fragrance chemical from turpentine sources used formaldehyde with P-pinene in a Prins reaction to produce the alcohol, Nopol (26) (59). 

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