Vinylic alcohols, oxidation

The chemical uses for ethylene prior to World War II were limited, for the most part, to ethylene glycol and ethyl alcohol. After the war, the demand for styrene and polyethylene took off, stimulating ethylene production and olefin plant construction. Todays list of chemical applications for ethylene reads like the WTiat s What of petrochemicals polyethylene, ethylbenzene (a precursor to styrene), ethylene dichloride, vinyl chloride, ethylene oxide, ethylene glycol, ethyl alcohol, vinyl acetate, alpha olefins, and linear alcohols are some of the more commercial derivatives of ethylene. The consumer products derived from these chemicals are found everywhere, from soap to construction materials to plastic products to synthetic motor oils. 

Ethylene is used in the manufacture of a wide range of chemicals (Fig. 3) including polyethylene (Figs. 4 and 5), styrene, alcohols, ethylene oxide, and vinyl chloride. 

IOB alone can oxidize some alcohols, but catalysed oxidations are much more efficient. Thus, in the presence of RuCl2(PPh3)2 primary aliphatic alcohols were oxidized cleanly to aldehydes, at room temperature the use of m-iodosylbenzoic acid instead of IOB considerably increased the yields for example, hexanal was formed from hexanol quantitatively (by GC) [19], Another catalytic system involved the use of simple lanthanide salts such as ytterbium triacetate [20]. Cyclic y-stannyl alcohols, readily available from cyclic vinyl ketones and Bu3SnLi, underwent oxidation accompanied by carbon-carbon bond cleavage (Grab fragmentation), when treated with IOB.BF3 and DCC. The products were unsaturated aldehydes or ketones. 

The synthesis of isolongistrobine also started with the imidazole ester 126, which in three steps was converted to the amino alcohol 129. Acylation with 4-pentenoyl chloride gave the amide alcohol 133. Oxidation of 133 with chromium trioxide in aqueous pyridine yielded the 4-pentene carboxamide 134. Oxidative splitting of the vinyl group of 134 with sodium periodate... 

A carbonyl transposition can be effected via the addition of a vinyl or an alkyl Grignard reagent to an a, 3-unsaturated ketone. Acid-catalyzed rearrangement of the resultant allylic alcohol during oxidation with PCC affords the transposed a,(3-unsaturated carbonyl substrate. This reaction represents a useful alternative when Wittig olefination of the ketone is problematic. 

See [6]. The following reaction types have been listed (a) Geometric isomerization of alkenes (b) Allylic [1,3] hydrogen shift (c) Cycloaddition of alkenes. Dimerization, Tri-merization. Polymerization (d) Skeletal rearrangments of alkenes and methathesis (e) Hydrogenation of alkenes (f) Additions to alkenes (g) Additions to C = X (h) Aliphatic substitutions (i) Aromatic substitution (j) Vinyl substitution (k) Oxidation of alkenes (1) Oxidation of alcohols (m) Oxidation of arenes (n) Oxidative decarboxylation (o) Oxidation of amines (p) Oxidation of vinylsilanes and sulfides (q) Oxidation of benzal-dehyde (r) Dehydrogenations. 

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