Conversion of methyl carlactonoate to heliolactone in sunflower

Takatoshi Wakabayashi1, Hikaru Shinde1, Nanami Shiotani2

  • 1Department of Agrobioscience, Graduate School of Agricultural Science, Kobe University, Kobe, Japan.

Natural Product Research
|October 9, 2020
PubMed

Related Concept Videos

Multiple Halogenation of Methyl Ketones: Haloform Reaction01:28

Multiple Halogenation of Methyl Ketones: Haloform Reaction

A method involving the transformation of methyl ketones to carboxylic acids using excess base and halogen is called the haloform reaction. It begins with the deprotonation of α hydrogen to form an enolate ion which reacts with the electrophilic halogen to give an α-halo ketone. The step continues until all the α protons are substituted to form a trihalomethyl ketone. The resulting molecule is unstable, and in the presence of a hydroxide base, it readily undergoes nucleophilic...
2.7K
Loss of Carboxy Group as CO2: Decarboxylation of Malonic Acid Derivatives01:35

Loss of Carboxy Group as CO2: Decarboxylation of Malonic Acid Derivatives

Just like β-keto acids—which upon thermal decarboxylation form ketones—β-dicarboxylic acids undergo decarboxylation to generate monocarboxylic acids with the liberation of carbon dioxide.
2.4K
Preparation of Carboxylic Acids: Hydrolysis of Nitriles01:19

Preparation of Carboxylic Acids: Hydrolysis of Nitriles

Nitriles (R–CN) can be converted into carboxylic acids (R–COOH) upon treatment with aqueous acids, i.e., upon hydrolysis of nitriles. Under base-catalyzed conditions, carboxylate anions (R–COO−) are formed.
5.6K
Alkylation of β-Diester Enolates: Malonic Ester Synthesis01:14

Alkylation of β-Diester Enolates: Malonic Ester Synthesis

Malonic ester synthesis is a method to obtain α substituted carboxylic acids from ꞵ-diesters such as diethyl malonate and alkyl halides.
3.9K
Acid Halides to Carboxylic Acids: Hydrolysis01:01

Acid Halides to Carboxylic Acids: Hydrolysis

Hydrolysis of acid halides is a nucleophilic acyl substitution reaction in which acid halides react with water to give carboxylic acids. The reaction occurs readily and does not require acid or a base catalyst.
As shown below, the mechanism involves a nucleophilic attack by water at the carbonyl carbon to form a tetrahedral intermediate. This is followed by the reformation of the carbon–oxygen π bond along with the departure of a halide ion. A final proton transfer step yields carboxylic...
3.3K
α-Halogenation of Carboxylic Acid Derivatives: Overview01:14

α-Halogenation of Carboxylic Acid Derivatives: Overview

Unlike aldehydes and ketones, carboxylic acids do not readily participate in α halogenation reactions via enols or enolate intermediates. However, α-halogenated acids are obtained through other methods. One of the approaches is the Hell–Volhard–Zelinsky (HVZ) reaction, wherein the carboxylic acid is treated with halogen in the presence of PBr3. It involves the conversion of acid to acid halide, which exists in equilibrium with its enol form. The enol attacks the...
3.9K