All Topics  
Ketal

 

 
   Email Print
   Bookmark   Link
 

 

Ketal
 
 
  Topics Ketal Topic Home

A ketal is a functional group
Functional group

In organic chemistry, functional groups are specific groups of atoms within molecules that are responsible for the characteristic chemical reactions of those molecules....
 or molecule
Molecule

In chemistry, a molecule is defined as a sufficiently stable, electric charge neutral group of at least two atoms in a definite arrangement held together by very strong chemical bonds....
 containing a carbon
Carbon

Carbon is a chemical element with chemical symbol C and atomic number 6. As a member of group 14 on the periodic table, it is nonmetallic and tetravalence?making four electrons available to form covalent bond chemical bonds....
 bonded
Chemical bond

A chemical bond is the physical process responsible for the attractive interactions between atoms and molecules, and that which confers stability to diatomic and polyatomic chemical compounds....
 to two -OR groups, where O is oxygen
Oxygen

Oxygen no O2 produced; 2) O2 produced, but absorbed in oceans & seabed rock; 3) O2 starts to gas out of the oceans, but is absorbed by land surfaces and formation of ozone layer; 4-5) O2 sinks filled and the gas accumulates]]...
 and R represents any alkyl
Alkyl

An alkyl is a univalent Radical consisting of carbon and hydrogen atoms, arranged in a chain. The Alkyls form homologous series with the general formula CnH2n+1....
 group. It is essentially equivalent to an acetal
Acetal

An acetal is a molecule with two single bonded oxygens attached to the same carbon atom.Traditional usages distinguish ketal from acetal . Current accepted terminology classifies ketals as a subset of acetals....
, and often the term acetal is used instead. The difference derives from the reaction which created the molecule. Acetals traditionally derive from the product of the reaction of an aldehyde
Aldehyde

An aldehyde is an organic compound containing a terminal carbonyl group. This functional group, which consists of a carbon atom bonded to a hydrogen atom and double bond to an oxygen atom , is called the aldehyde group....
 with excess of alcohol
Alcohol

In chemistry, an alcohol is any organic compound in which a hydroxyl Functional group is bound to a carbon atom of an alkyl or substituted alkyl group....
, whereas the name ketal derives from the product of the reaction of a ketone
Ketone

In organic chemistry, a ketone is a type of organic compound which contains a carbonyl group bonded to two other carbon atoms in the form:Neither of the substituents R1 and R2 may be equal to hydrogen ....
 with excess alcohol.






Discussion
Ask a question about 'Ketal'
Start a new discussion about 'Ketal'
Answer questions from other users
Full Discussion Forum



Encyclopedia


A ketal is a functional group
Functional group

In organic chemistry, functional groups are specific groups of atoms within molecules that are responsible for the characteristic chemical reactions of those molecules....
 or molecule
Molecule

In chemistry, a molecule is defined as a sufficiently stable, electric charge neutral group of at least two atoms in a definite arrangement held together by very strong chemical bonds....
 containing a carbon
Carbon

Carbon is a chemical element with chemical symbol C and atomic number 6. As a member of group 14 on the periodic table, it is nonmetallic and tetravalence?making four electrons available to form covalent bond chemical bonds....
 bonded
Chemical bond

A chemical bond is the physical process responsible for the attractive interactions between atoms and molecules, and that which confers stability to diatomic and polyatomic chemical compounds....
 to two -OR groups, where O is oxygen
Oxygen

Oxygen no O2 produced; 2) O2 produced, but absorbed in oceans & seabed rock; 3) O2 starts to gas out of the oceans, but is absorbed by land surfaces and formation of ozone layer; 4-5) O2 sinks filled and the gas accumulates]]...
 and R represents any alkyl
Alkyl

An alkyl is a univalent Radical consisting of carbon and hydrogen atoms, arranged in a chain. The Alkyls form homologous series with the general formula CnH2n+1....
 group. It is essentially equivalent to an acetal
Acetal

An acetal is a molecule with two single bonded oxygens attached to the same carbon atom.Traditional usages distinguish ketal from acetal . Current accepted terminology classifies ketals as a subset of acetals....
, and often the term acetal is used instead. The difference derives from the reaction which created the molecule. Acetals traditionally derive from the product of the reaction of an aldehyde
Aldehyde

An aldehyde is an organic compound containing a terminal carbonyl group. This functional group, which consists of a carbon atom bonded to a hydrogen atom and double bond to an oxygen atom , is called the aldehyde group....
 with excess of alcohol
Alcohol

In chemistry, an alcohol is any organic compound in which a hydroxyl Functional group is bound to a carbon atom of an alkyl or substituted alkyl group....
, whereas the name ketal derives from the product of the reaction of a ketone
Ketone

In organic chemistry, a ketone is a type of organic compound which contains a carbonyl group bonded to two other carbon atoms in the form:Neither of the substituents R1 and R2 may be equal to hydrogen ....
 with excess alcohol. Although this term had been abandoned, it has been reinstated by IUPAC as a subclass of acetals. Ketals have the general form shown on the right, where R, R', R, and R are carbon backbones. If R = H
Hydrogen

Hydrogen is the chemical element with atomic number 1. It is represented by the chemical symbol H. At standard temperature and pressure, hydrogen is a colorless, odorless, nonmetallic, tasteless, highly combustion and explosive Diatomic molecule gas with the molecular formula H2....
, the structure is a traditional acetal
Acetal

An acetal is a molecule with two single bonded oxygens attached to the same carbon atom.Traditional usages distinguish ketal from acetal . Current accepted terminology classifies ketals as a subset of acetals....
.

Ketals and acetals can be used as carbonyl
Carbonyl

In organic chemistry, a carbonyl group is a functional group composed of a carbon atom double bond to an oxygen atom : C=O.The term carbonyl can also refer to carbon monoxide as a ligand in an inorganic or organometallic complex ; in this situation, carbon is triple-bonded to oxygen : C=O....
-protecting group
Protecting group

A protecting group or protective group is introduced into a molecule by chemical modification of a functional group in order to obtain chemoselectivity in a subsequent chemical reaction....
s.

Reactions


Synthesis


Although there are plenty ways to synthesize a ketal, they are generally made using an alcohol
Alcohol

In chemistry, an alcohol is any organic compound in which a hydroxyl Functional group is bound to a carbon atom of an alkyl or substituted alkyl group....
, an acid
Acid

An acid is traditionally considered any chemical compound that, when dissolved in water, gives a solution with a hydrogen ion Activity greater than in pure water, i.e....
 catalysis and any way to remove water from the reaction (e.g. a Dean-Stark apparatus
Dean-Stark apparatus

The Dean-Stark apparatus or Dean-Stark receiver or distilling trap is a piece of laboratory glassware used in synthetic chemistry to collect water from a reactor....
), driving the equilibrium of the reaction to the completion.

Acetals formed from ketones were originally called ketals. The name was dropped recently from IUPAC system of naming compounds, so the products of addition of two equivalents of alcohol to both aldehydes and ketones are called acetals.

Ketals and acetals can, under acidic conditions, be converted back into a hemiacetal
Hemiacetal

Hemiacetals and hemiketals are compounds of the general formula R1R'1COR2, where R2 is not hydrogen....
 and an alcohol
Alcohol

In chemistry, an alcohol is any organic compound in which a hydroxyl Functional group is bound to a carbon atom of an alkyl or substituted alkyl group....
, as the entire reaction
Reaction

Reaction may refer to:*Response to another event*Adverse drug reaction*Chemical reaction*Light reaction*Nuclear reaction*Reaction , as defined by Newton's third law...
 is an equilibrium
Chemical equilibrium

In a chemical process, chemical equilibrium is the state in which the Activity or concentrations of the reactants and products have no net change over time....
.

See also


  • Functional group
    Functional group

    In organic chemistry, functional groups are specific groups of atoms within molecules that are responsible for the characteristic chemical reactions of those molecules....
  • Fructone
    Fructone

    Fructone, also known as apple ketal and applinal, is a chemical synthesis aroma compound with a fruity, apple-like smell with pineapple, strawberry, and woody aspects reminding of sweet pine....
    , an ethylene glycol ketal and aroma compound