The Ireland-Claisen (also known as the ester enolate Claisen rearrangement) uses lithium diisopropylamide (LDA), trimethylsilyl chloride (TMSCI), sodium hydroxide, and water to convert an allyl ester to a γ, δ-unsaturated carboxylic acid. The α-hydrogen of the allyl ester is deprotonated by LDA, creating an enolate, which attacks TMSCl, releasing LiCl...
The Gabriel synthesis uses phthalimide, a base, an alkyl halide, and hydrazine to make a 1° amine in a two-step process. First phthalimide is alkylated with an alkyl halide via an SN2 reaction, forming N-alkylphthalimide. Next, hydrazine attacks a carbonyl group of N-alkylphthalimide, resulting in the ring opening, followed by...
Adding a keto group to an aromatic or aliphatic substrate using an acyl halide or anhydride in the presence of a Lewis acid catalyst is called the Friedel-Crafts acylation. The reactive electrophile in this aromatic substitution is either an acylium ion or an acyl chloride-Lewis acid complex. [1] Benzene and...
The Baeyer-Villiger oxidation reaction uses an oxidizing agent such as peroxyacid to convert ketones or cyclic ketones to esters and lactones/ hydroxy acid respectively. Peroxyacid first attacks a protonated carbonyl group, forming a tetrahedral intermediate named the Criegee intermediate. An alkyl migration and loss of carboxylic acid then takes place...
The Fischer indole synthesis uses a protic or Lewis acid catalyst to convert a phenylhydrazine and an aldehyde or ketone to an indole. The phenylhydrazine makes an iminium ion with the carbonyl compound, which tautomerizes to the ene-hydrazine. A [3,3]-sigmatropic rearrangement disrupts the aromatic ring, but a subsequent proton transfer...
The Fischer esterification uses a catalytic acid to convert a carboxylic acid and alcohol to an ester. Protonation of the carbonyl oxygen activates the carboxylic acid to nucleophilic attack by the alcohol, producing a tetrahedral intermediate with two hydroxyl groups. Ester formation occurs when a proton is transferred to one...