Carbonyl compounds, simple

Carbonyl compounds, simple, enolisation and related reactions of, 18, 1... 

Imines and Carbonyl Compounds. Simple 2-alkyl(aryl)-5-(4//)-oxazolones like 191 can react with aldehydes, ketones, imines, and oximes to afford the corresponding unsaturated analogues 192 (Scheme 7.58). In some cases, this procedure is especially advantageous over the classical one-pot synthesis.The chemistry of unsaturated 5(4//)-oxazolones like 192 will be discussed in detail in Section 7.4. 

Carbonyl compounds, reversible hydration of, 4, 1 Carbonyl compounds, simple, enolisation and related reactions of, 18, 1 Carboxylic acids, tetrahedral intermediates derived from, spectroscopic detection and investigation of their properties, 21, 37... 

The most significant feature of the spectrum shown is the strong C=0 stretch at 1688 cm which is characteristic of aromatic carbonyl compounds (simple saturated carbonyl compounds have a C=0 stretch at about 1720 cm M The presence of a benzene ring can be confirmed by the moderate to strong bands at 1601/ 1585, 1500 and 1450 cm". These absorptions are characteristic of the C=C stretch of benzene derivatives. Further spectral evidence supporting the hypothesis of a carbonyl functionality can be seen by the two weak bands at 2750 cm" and 2820 cm . These absorptions are characteristic of the C-H stretch of aldehydes. Another important feature of this spectrum is the moderate band at 1050 cm which is the typical absorption of the C-0 stretch of ethers. We now know that compound P is an aromatic aldehyde with a possible ether linkage. 

Reaction with Enolates. TV-Fluorobenzenesulfonimide readily reacts with enolates to yield a-fluoro carbonyl compounds. Simple ketone enolates, prepared by treatment with hthlum his (trimethylsilyl)amide in THF at low temperature, are fluorinated by treatment with a molar equivalent of NFSi (eq 4). ... 

Reactions of Carbonyl Compounds Simple Reversible Additions... 

Other microorganisms have also been used for the asymmetric reduction of carbonyl compounds. Simple ahphatic ketones as well as aromatic ketones can be reduced with very high enantioselectivity by using biocatalysts. For example, aliphatic ketones such as... 

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