CANNIZARO REACTION - COMPLETE REVISION скачать в хорошем качестве

CANNIZARO REACTION - COMPLETE REVISION

The Cannizzaro reaction is a chemical process involving the base-induced disproportionation of aldehydes that lack alpha-hydrogen atoms (non-enolizable aldehydes). In this redox reaction, two molecules of the aldehyde react in the presence of a strong concentrated base (such as sodium hydroxide or potassium hydroxide) to produce one molecule of a primary alcohol and one molecule of a carboxylic acid salt. Key Characteristics and Mechanism: Conditions: Requires non-enolizable aldehydes (e.g., formaldehyde, benzaldehyde) and a concentrated base. Disproportionation: The same aldehyde molecule acts as both an oxidizing agent and a reducing agent. Mechanism: The reaction begins with the nucleophilic attack of a hydroxide ion on the carbonyl carbon of the aldehyde, forming a tetrahedral intermediate. This intermediate then releases a hydride ion, which attacks a second molecule of the aldehyde. Result: One molecule is reduced to an alcohol, while the other is oxidized to a carboxylic acid. Examples and Variations: Formaldehyde: When treated with a strong base, formaldehyde undergoes a Cannizzaro reaction to produce methanol and formic acid. Benzaldehyde: Benzaldehyde reacts in a basic medium to yield benzyl alcohol and sodium benzoate. Crossed Cannizzaro Reaction: A more efficient variation where two different non-enolizable aldehydes are used, often using formaldehyde as a sacrificial agent to reduce another valuable aldehyde to an alcohol. Differences from Aldol Condensation: Unlike Aldol condensation, which occurs with aldehydes that possess alpha-hydrogens, the Cannizzaro reaction is specifically for those that do not, as the absence of alpha-hydrogen prevents the formation of an enol #neet2026 #jee2026 #jeemains #cannizaroreaction #carbonylcompounds #crosscannizaro #neetmumbra #organicchemistry #booster #chemistrybooster #viralvideos #mumbra #kausa #mumbrakausa #conceptneetacademy #conceptneetdigital #neetmumbra #bestrevision