Synthesis and Characterization of Aldehydes and Ketones.pptx

Synthesis and Characterization of Aldehydes and Ketones

1. SYNTHESIS AND CHARACTERIZATION OF ALDEHYDES AND KETONES PRESENTED BY: Mostafa Sayed Ahmed Zahry ID: 1240072

2. Aldehydes and ketones are important classes of organic compounds containing the carbonyl functional group (C=O). Their synthesis and characterization are crucial aspects of organic chemistry. Overview

3. In oxidation reactions, electrons are transferred from one substance to another. The substance that loses electrons is oxidized, while the one that gains electrons is reduced. Oxidation involves an increase in the oxidation state of the substance being oxidized. This can occur through the addition of oxygen, removal of hydrogen, or loss of electrons. Oxidation reactions do not occur in isolation. They are always paired with reduction reactions, where the overall process is called a redox reaction. Characteristics of Oxidation Reactions

4. Oxidation of Alcohols One of the most common methods for synthesizing aldehydes and ketones is through the oxidation of alcohols3 Primary alcohols can be oxidized to aldehydes using mild oxidizing agents like pyridinium chlorochromate (PCC) or Dess-Martin periodinane. Secondary alcohols are oxidized to ketones using oxidizing agents such as chromic acid or Jones reagent. Tertiary alcohols cannot be oxidized further. Synthesis Methods

5. Ozonolysis of Alkenes Ozonolysis is a powerful method for cleaving carbon-carbon double bonds to form carbonyl compounds Alkenes react with ozone to form ozonides, which are then reduced to form aldehydes or ketones. The product depends on the substitution pattern of the original alkene. Synthesis Methods

6. Hydration and Hydroboration of Alkynes Alkynes can be transformed into carbonyl compounds through hydration or hydroboration reactions Hydration of terminal alkynes yields aldehydes, while internal alkynes produce ketones. Hydroboration-oxidation of alkynes results in the formation of ketones. Synthesis Methods

7. Spectroscopic Methods Infrared (IR) Spectroscopy: Aldehydes and ketones show characteristic C=O stretching bands around 1700-1740 cm⁻¹. Nuclear Magnetic Resonance (NMR) Spectroscopy:¹H NMR: Aldehyde protons appear as singlets around 9-10 ppm. ¹³C NMR: Carbonyl carbons resonate around 190-205 ppm. Mass Spectrometry: Provides information about molecular mass and fragmentation patterns. Characterization Techniques

8. Characterization Techniques Chemical Tests 2,4-Dinitrophenylhydrazine (Brady's reagent): Forms orange-red precipitates with aldehydes and ketones. Tollens' Test: Aldehydes reduce silver ions to form a silver mirror, while ketones do not react. Fehling's Test: Aldehydes reduce copper(II) to copper(I) oxide, producing a red precipitate.

9. The synthesis and characterization of aldehydes and ketones have significant applications in various fields:Pharmaceutical Industry: Many drugs contain carbonyl groups, and their synthesis is crucial in drug development. Materials Science: Aldehydes and ketones are used in the production of polymers and advanced materials. Fragrance Industry: Many aromatic compounds used in perfumes are aldehydes or ketones. Practical Applications

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