Alcohols interesting examples

The following schemes represent some interesting examples where the TBDMS group is introduced selectively on compounds with more than one alcohol. 

Another interesting example of dehydrative C-C coupling involves the alkylation of benzimidazole 36 with allyl alcohol 37, which is catalysed by complex 39 [15], The reaction is believed to proceed by alkene complex formation with the allyl alcohol 37 with loss of water from the NH proton of the NHC ligand and OH of the allyl alcohol to give an intermediate Ji-allyl complex. The initially formed 2-allylbenzimidazole isomerises to a mixture of the internal alkenes 38 (Scheme 11.9). 

Of particular interest are oxidations of unsaturated alcohols, for example, oxidation of cinnamyl alcohol to cinnamaldehyde,74,75 and special promoters have been added to increase selectivity (Fig. 6.13).75 Although the functions of these promoters are still not fully undestood, some authors attribute their increased selectivity to physical blocking of reaction sites. This blocking reduces the size of the active site ensemble and suppresses the tendency for alcohols to strongly adsorb and dissociate on Pt.75... 

An interesting example of hydrogenation with hydrogen in the absence of transition metal catalyst is reduction of benzophenone to benzhydrol with hydrogen in /er/-butyl alcohol containing potassium /er/-butoxide at 150-210° and 96-135 atm. Although the yields range from 47 to 98% the method is not practical because of its drastic conditions, and because of a cornucopia of more suitable reductions. 

The remaining chapters deal with a variety of catalysts for effecting oxidation reactions. Chapter 5 describes three simple protocols for the controlled oxidation of primary or secondary alcohols. The importance of stereocontrolled epoxidation and hydroxylation reactions is reflected by the fact that Chapter 6, directed at this field, is one of the most extensive sections of the book. An interesting example of an enantioselective Baeyer-Villiger reaction is featured in Chapter 7, together with an industrially important ketone to enone conversion. Oxidative carbon-carbon... 

The reaction proceeded with extremely high syn diastereocontrol with five- and six-membered cyclic allylic alcohols with a variety of zinc carbenoids. One particnlarly interesting example of a highly functionalized starting material is in the introduction of the C19 methyl group of taxusin through a highly chemo- and diastereoselective cyclo-propanation (equation 50). ... 

An interesting example of alkylation with alcohols is the selective transformation of isomeric phenylpropanols under appropriate reaction conditions 199... 

An interesting example of the salting out by nonelectrolytes in water was given by Grigorovich and Samoilov (69). They studied the solubility of praseodymium chloride and sulfate in water in the presence of various nonelectrolytes (methyl alcohol, ethyl alcohol, and diethyl ether.) Their results show that the decrease in solubility of praseodymium chloride is only of the order of a few percent but that this decrease is probably highly significant because praseodymium chloride is more soluble in pure methyl and ethyl alcohol than in pure water. (The... 

The dicarboxylation of 2-methyl-4-penten-2-ol provides an interesting example in that palladium car-boxylate is generated from the pentenol alcohol function producing a "y-lactone (Scheme 13).93... 

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