Mechanism · 5 of 5 Mechanism videos Every named mechanism from Organic 1 & 2, organized into 13 topics. Each reaction is shown in order of the Klein text; select any reaction to watch the arrow-pushing mechanism video.
All 109 Substitution & elimination Addition to alkenes Alkyne chemistry Radical chemistry Alcohols & thiols Ethers, epoxides & sulfur Extended pi systems Aromaticity & benzylic Aromatic substitutions Aldehydes & ketones Carboxylic acids & derivatives Alpha-carbon reactions Amines
Substitution & elimination 10 Backside attack inverts the stereocenter in one step. Concerted anti-periplanar loss of H and X gives an alkene. The substrate ionizes to a carbocation, then solvent attacks. A carbocation forms, then loss of a beta-proton gives the alkene. The planar cation is attacked from both faces, giving racemic product. A tosylate leaving group is displaced with inversion. A hydride or alkyl shift builds a more stable cation. The cation rearranges before eliminating to an alkene. A protonated alcohol is displaced by halide via SN2. A protonated alcohol ionizes, then halide traps the cation. Addition to alkenes 10 Markovnikov addition of H and X across the double bond. The intermediate cation shifts before halide adds. Markovnikov addition of water through a carbocation. Markovnikov hydration with no rearrangement. Anti-Markovnikov, syn addition of water. Anti addition of Br2 through a bromonium ion. Br2 in water opens the bromonium to a halohydrin. An epoxide is opened to give a trans-diol. OsO4 adds two OH groups on the same face. Ozone cleaves the alkene into two carbonyls. Alkyne chemistry 4 Double elimination of a dihalide builds the triple bond. Markovnikov addition of water gives a ketone. The enol rearranges to the more stable ketone. An acetylide anion attacks an alkyl halide. Radical chemistry 4 A chain mechanism substitutes Cl onto an alkane. NBS supplies a low Br2 level to brominate the allylic site. Peroxides give anti-Markovnikov HBr addition. Radicals chain-link alkene monomers into a polymer. Alcohols & thiols 12 Hydroxide displaces a leaving group to give an alcohol. A carbocation is trapped by water. Acid-catalyzed Markovnikov hydration of an alkene. Anti-Markovnikov alcohol from an alkene. NaBH4 reduces a carbonyl to an alcohol. LiAlH4 reduces an ester to a primary alcohol. A Grignard reagent adds to give a tertiary alcohol. Two equivalents of Grignard give a tertiary alcohol. Converts an alcohol into an alkyl chloride. Converts an alcohol into an alkyl bromide. Chromic acid oxidizes it to a ketone. Chromic acid oxidizes it to a carboxylic acid. Ethers, epoxides & sulfur 10 Two alcohols condense to a symmetrical ether. An alkoxide does SN2 on an alkyl halide. HX cleaves an ether into two fragments. Ethers form explosive peroxides on standing in air. A peroxyacid delivers an oxygen to make an epoxide. Base closes a halohydrin into an epoxide. Nucleophile attacks the less hindered carbon. Nucleophile attacks the more substituted carbon. A thiolate displaces a leaving group. Two thiols oxidize to a disulfide. Extended pi systems 2 1,2- versus 1,4-addition to a conjugated diene. A diene and dienophile form a cyclohexene ring. Aromaticity & benzylic 4 NBS brominates the benzylic position by radicals. A resonance-stabilized benzylic cation forms. Elimination proceeds through a benzylic cation. Addition occurs at the benzylic position. Aromatic substitutions 12 Electrophilic aromatic bromination of benzene. A reversible SO3 substitution onto the ring. The nitronium ion substitutes onto benzene. A carbocation alkylates the aromatic ring. An acylium ion installs a ketone group. The activated ring brominates readily. A protected phenol directs the bromination. The meta-directing carboxyl controls the site. Chlorine directs the electrophile ortho and para. Addition–elimination through a Meisenheimer complex. Strong base eliminates to a strained benzyne. Benzyne is trapped by a diene in a cycloaddition. Aldehydes & ketones 15 A nucleophile adds directly to the carbonyl. A protonated carbonyl is attacked by a nucleophile. Water adds under base to form a gem-diol. Water adds under acid to form a gem-diol. An aldehyde plus two alcohols gives an acetal. Aqueous acid reverts an acetal to the carbonyl. A primary amine condenses to an imine. A secondary amine condenses to an enamine. A hydrazone reduces the carbonyl to CH2. Two thiols convert the carbonyl to a dithiane. NaBH4 or LAH reduce the carbonyl to an alcohol. A Grignard reagent gives a tertiary alcohol. HCN adds to give a cyanohydrin. An ylide converts the carbonyl into an alkene. A peroxyacid inserts oxygen to form an ester. Carboxylic acids & derivatives 10 A nitrile hydrolyzes to a carboxylic acid. Base hydrolyzes a nitrile to a carboxylate. A Grignard reagent plus CO2 gives a carboxylic acid. An amine converts an ester into an amide. Acid and alcohol form an ester reversibly. Base hydrolyzes an ester to a carboxylate. Acid hydrolyzes an ester to acid plus alcohol. Acid hydrolyzes an amide to a carboxylic acid. Base hydrolyzes an amide to a carboxylate. A Grignard adds to a nitrile to form a ketone. Alpha-carbon reactions 14 Acid-catalyzed halogenation at the alpha carbon. Alpha-bromination of a carboxylic acid. An enolate adds then dehydrates to an enone. An aldol between two different carbonyls. A ring-forming aldol condensation. Two esters give a beta-keto ester. An intramolecular Claisen forms a ring. An enolate is alkylated by an alkyl halide. Builds substituted acetic acids. Builds substituted methyl ketones. A beta-keto acid loses CO2 on heating. Conjugate addition to an enone. 1,4-addition of a cuprate to an enone. A Michael then aldol builds a new ring. Amines 2 A phthalimide route to a clean primary amine. An imine is reduced to give an amine.