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Aldehydes and Ketones. Structure. Structure. Nomenclature of aldehydes. Aldehydes are named by adding the suffix - al to the name of the corresponding hydrocarbon. The carbonyl carbon is given the number 1 . ethanal acetaldehyde. Nomenclature of aldehydes. Nomenclature of aldehydes.
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Nomenclature of aldehydes Aldehydes are named by adding the suffix -alto the name of the corresponding hydrocarbon. The carbonyl carbon is given the number 1. ethanal acetaldehyde
Nomenclature of aldehydes When -CHO is attached to a ring, the suffix carbaldehyde is used. benzenecarbaldehyde benzaldehyde 3-methylpentanal
Nomenclature of ketones Ketones are named using the name of the corresponding hydrocarbon followed by the suffix -one. The position of the carbonyl carbon must be indicated. propanone acetone dimethyl ketone One can also name the two radicals, R and R’, followed by the word ketone.
Nomenclature of ketones ethyl methyl ketone 1-phenyl-2-propanone benzyl methyl ketone
Nomenclature of ketones diphenylmethanone benzophenone phenylethanone acetophenone
Synthesis of aldehydes - oxidation of primary alcohols PCC = pyridinium chlorochromate
Rosemund reduction RCHO or ArCHO A special catalyst is used: palladium on barium sulfate which has been deactivated (poisoned) with an amine such as quinoline.
Keto - enol tautomerism Structural isomers that are formally related only by the shift of a hydrogen and one or more bonds are called tautomers.
Oxidation of aldehydes RCO2H or ArCO2H
Tollens’ test colorless solution silver mirror
Addition of cyanide cyanohydrin
Reduction to alcohols hydride transfer
Reduction to hydrocarbons Zn(Hg), conc. HCl Clemmensen reduction Wolff-Kishner reduction
Reduction to hydrocarbons an antiseptic
Reactions of acetals H + H + H O 2ROH + R'-C=O 'R C OR 2 OR H
Wittig reaction + (C6H5)3PO triphenylphosphine oxide an ylid Georg Wittig, University of Heidelberg, Nobel Prize 1979
Wittig reaction - ylid formation alkyltriphenylphosphonium halide triphenylphosphine an ylid