Intramolecular Diels-Alder Cycloaddition
Encyclopedia
In organic chemistry, an intramolecular Diels-Alder cycloaddition is a Diels–Alder reaction in which the diene
and a dienophile are both part of the same molecule. The reaction leads to the formation of one new double bond and two new sigma bonds, but this time the ultimate product is a fused or bridged cyclic ring.
The tether than attaches the two reacting groups also affects the geometry of the reaction. As a result of its conformational
and other structural restrictions, the exo vs endo results are usually not based on the simple (intermolecular) Diels–Alder reaction effects.
cycloaddition is extremely useful for the formation of naturally occurring polycyclic rings. The reaction provides ready access to polycyclic compounds with a great deal of stereoselectivity
. The following are several useful drugs whose complete synthesis have been accomplished using the intramolecular Diels-Alder reaction.
, the cause of “early blight” in tomato and potato plants. The drug is being look as an anti-cancer medication.
. Salvinorin A
is a potent and selective κ-opioid receptor. The compound has potential uses in psychotherapuetic treatments and Alzheimer’s treatment.
Diene
In organic chemistry a diene or diolefin is a hydrocarbon that contains two carbon double bonds.Conjugated dienes are functional groups, with a general formula of CnH2n-2. Dienes and alkynes are functional isomers...
and a dienophile are both part of the same molecule. The reaction leads to the formation of one new double bond and two new sigma bonds, but this time the ultimate product is a fused or bridged cyclic ring.
Reaction products
Because the two reacting groups are already attached, two basic modes of addition are possible in this reaction. Depending on whether the tether that links to the dienophile is attached to the end or the middle of the diene, fused or bridged polycyclic ring systems can be formed.The tether than attaches the two reacting groups also affects the geometry of the reaction. As a result of its conformational
Conformational isomerism
In chemistry, conformational isomerism is a form of stereoisomerism in which the isomers can be interconverted exclusively by rotations about formally single bonds...
and other structural restrictions, the exo vs endo results are usually not based on the simple (intermolecular) Diels–Alder reaction effects.
Applications
Intramolecular Diels-AlderDiels-Alder reaction
The Diels–Alder reaction is an organic chemical reaction between a conjugated diene and a substituted alkene, commonly termed the dienophile, to form a substituted cyclohexene system. The reaction can proceed even if some of the atoms in the newly formed ring are not carbon...
cycloaddition is extremely useful for the formation of naturally occurring polycyclic rings. The reaction provides ready access to polycyclic compounds with a great deal of stereoselectivity
Stereoselectivity
In chemistry, stereoselectivity is the property of a chemical reaction in which a single reactant forms an unequal mixture of stereoisomers during the non-stereospecific creation of a new stereocenter or during the non-stereospecific transformation of a pre-existing one...
. The following are several useful drugs whose complete synthesis have been accomplished using the intramolecular Diels-Alder reaction.
Solanapyrone A
Solanapyrone A is an inhibitor of mammalian DNA polymerase β and λ, repair type DNA polymerase. The compound was isolated from the phytopathogenic fungi Alternaria solaniAlternaria solani
Alternaria solani is a fungal pathogen, producing a disease in tomato and potato plants called early blight. The pathogen produces distinctive "bullseye" patterned leaf spots and can also cause stem lesions and fruit rot on tomato and tuber blight on potato. Despite the name "early," foliar...
, the cause of “early blight” in tomato and potato plants. The drug is being look as an anti-cancer medication.
Salvinorin A
Isolated from the hallucinogenic sage, Salvia DivinorumSalvia divinorum
Salvia divinorum is a psychoactive plant which can induce dissociative effects and is a potent producer of "visions" and other hallucinatory experiences...
. Salvinorin A
Salvinorin A
Salvinorin A is the main active psychotropic molecule in Salvia divinorum, a Mexican plant which has a long history of use as an entheogen by indigenous Mazatec shamans...
is a potent and selective κ-opioid receptor. The compound has potential uses in psychotherapuetic treatments and Alzheimer’s treatment.