Acylals in organic chemistry are a group of chemical compounds sharing a functional group with the general structure RCH(OOCR)2. Acylals are obtained by reaction of carbonyls with acetic anhydride or other acid anhydrides and a suitable catalyst, for instance with sulfated zirconia [1] at low temperatures when used as protective groups for aldehydes. High temperature exposure converts the acylal back to the aldehyde.
In organic chemistry, a ketone is an organic compound with the structure R−C(=O)−R', where R and R' can be a variety of carbon-containing substituents. Ketones contain a carbonyl group −C(=O)−. The simplest ketone is acetone, with the formula (CH3)2CO. Many ketones are of great importance in biology and in industry. Examples include many sugars (ketoses), many steroids, and the solvent acetone.
Cubic zirconia (abbreviated CZ) is the cubic crystalline form of zirconium dioxide (ZrO2). The synthesized material is hard and usually colorless, but may be made in a variety of different colors. It should not be confused with zircon, which is a zirconium silicate (ZrSiO4). It is sometimes erroneously called cubic zirconium.
Zirconium dioxide, sometimes known as zirconia, is a white crystalline oxide of zirconium. Its most naturally occurring form, with a monoclinic crystalline structure, is the mineral baddeleyite. A dopant stabilized cubic structured zirconia, cubic zirconia, is synthesized in various colours for use as a gemstone and a diamond simulant.
In organic chemistry, the Swern oxidation, named after Daniel Swern, is a chemical reaction whereby a primary or secondary alcohol is oxidized to an aldehyde or ketone using oxalyl chloride, dimethyl sulfoxide (DMSO) and an organic base, such as triethylamine. It is one of the many oxidation reactions commonly referred to as 'activated DMSO' oxidations. The reaction is known for its mild character and wide tolerance of functional groups.
An aldol condensation is a condensation reaction in organic chemistry in which two carbonyl moieties react to form a β-hydroxyaldehyde or β-hydroxyketone, and this is then followed by dehydration to give a conjugated enone.
Fischer esterification or Fischer–Speier esterification is a special type of esterification by refluxing a carboxylic acid and an alcohol in the presence of an acid catalyst. The reaction was first described by Emil Fischer and Arthur Speier in 1895. Most carboxylic acids are suitable for the reaction, but the alcohol should generally be primary or secondary. Tertiary alcohols are prone to elimination. Contrary to common misconception found in organic chemistry textbooks, phenols can also be esterified to give good to near quantitative yield of products. Commonly used catalysts for a Fischer esterification include sulfuric acid, p-toluenesulfonic acid, and Lewis acids such as scandium(III) triflate. For more valuable or sensitive substrates other, milder procedures such as Steglich esterification are used. The reaction is often carried out without a solvent or in a non-polar solvent to facilitate the Dean-Stark method. Typical reaction times vary from 1–10 hours at temperatures of 60-110 °C.
In organic chemistry, ozonolysis is an organic reaction where the unsaturated bonds are cleaved with ozone. Multiple carbon–carbon bond are replaced by carbonyl groups, such as aldehydes, ketones, and carboxylic acids. The reaction is predominantly applied to alkenes, but alkynes and azo compounds are also susceptible to cleavage. The outcome of the reaction depends on the type of multiple bond being oxidized and the work-up conditions.
An organic acid anhydride is an acid anhydride that is also an organic compound. An acid anhydride is a compound that has two acyl groups bonded to the same oxygen atom. A common type of organic acid anhydride is a carboxylic anhydride, where the parent acid is a carboxylic acid, the formula of the anhydride being (RC(O))2O. Symmetrical acid anhydrides of this type are named by replacing the word acid in the name of the parent carboxylic acid by the word anhydride. Thus, (CH3CO)2O is called acetic anhydride.Mixed (or unsymmetrical) acid anhydrides, such as acetic formic anhydride (see below), are known, whereby reaction occurs between two different carboxylic acids. Nomenclature of unsymmetrical acid anhydrides list the names of both of the reacted carboxylic acids before the word "anhydride" (for example, the dehydration reaction between benzoic acid and propanoic acid would yield "benzoic propanoic anhydride").
The Pummerer rearrangement is an organic reaction whereby an alkyl sulfoxide rearranges to an α-acyloxy–thioether (monothioacetal-ester) in the presence of acetic anhydride.
The Banert cascade is an organic reaction in which an NH-1,2,3-triazole is prepared from a propargyl halide or sulfate and sodium azide in a dioxane- water mixture at elevated temperatures. It is named after Klaus Banert, who first reported the process in 1989. This cascade reaction is unusual because it consists of two consecutive rearrangement reactions.
Idose is a hexose, a six carbon monosaccharide. It has an aldehyde group and is an aldose. It is not found in nature, but its uronic acid, iduronic acid, is important. It is a component of dermatan sulfate and heparan sulfate, which are glycosaminoglycans. The first and third hydroxyls point the opposite way from the second and fourth. It is made by aldol condensation of D- and L-glyceraldehyde. L-Idose is a C-5 epimer of D-glucose.
The Rosenmund reduction is a hydrogenation process in which an acyl chloride is selectively reduced to an aldehyde. The reaction was named after Karl Wilhelm Rosenmund, who first reported it in 1918.
Sodium bis(2-methoxyethoxy)aluminium hydride (SMEAH; trade names Red-Al, Synhydrid, Vitride) is a complex hydride reductant with the formula NaAlH2(OCH2CH2OCH3)2. The trade name Red-Al refers to its being a reducing aluminium compound. It is used predominantly as a reducing agent in organic synthesis. The compound features a tetrahedral aluminium center attached to two hydride and two alkoxide groups, the latter derived from 2-methoxyethanol. Commercial solutions are colorless/pale yellow and viscous. At low temperatures (below -60 °C), the solution solidifies to a glassy pulverizable substance with no sharp melting point.
The Wohl degradation in carbohydrate chemistry is a chain contraction method for aldoses. The classic example is the conversion of glucose to arabinose as shown below. The reaction is named after the German chemist Alfred Wohl (1863–1939).
The Erlenmeyer–Plöchl azlactone and amino acid synthesis, named after Friedrich Gustav Carl Emil Erlenmeyer who partly discovered the reaction, is a series of chemical reactions which transform an N-acyl glycine to various other amino acids via an oxazolone.
In enzymology, an adenylylsulfatase is an enzyme that catalyzes the chemical reaction
In enzymology, a phosphoadenylylsulfatase (EC 3.6.2.2) is an enzyme that catalyzes the chemical reaction
The Parikh–Doering oxidation is an oxidation reaction that transforms primary and secondary alcohols into aldehydes and ketones, respectively. The procedure uses dimethyl sulfoxide (DMSO) as the oxidant and the solvent, activated by the sulfur trioxide pyridine complex (SO3•C5H5N) in the presence of triethylamine or diisopropylethylamine as base. Dichloromethane is frequently used as a cosolvent for the reaction.
Alniditan is a 5-HT1D receptor agonist with migraine-preventive effects.
The Boekelheide reaction is a rearrangement of α-picoline-N-oxides to hydroxymethylpyridines. It is named after Virgil Boekelheide who first reported it in 1954. Originally the reaction was carried out using acetic anhydride, which typically required a period at reflux (~140 °C). The reaction can be performed using trifluoroacetic anhydride (TFAA), which often allows for a room temperature reaction.