What happens when furan reacts with maleic anhydride?
16 Furan and maleic anhydride can be used to produce phthalic anhydride (4) in a two-step process: Diels–Alder cyclo- addition to produce 3 followed by dehydration. A related product that can be prepared following this approach is the synthesis of p-xylene from dimethylfuran and ethylene.
Does furan give Diels-Alder reaction?
The resonance stabilization of furan is only 67 kJ/mol compared to 150 kJ/mol for benzene. The aromatic π system of furan can be disrupted if a process is energetically favourable. Thus, furan readily undergoes Diels-Alder reactions and reacts as a diene in the presence of a dienophile.
When maleic anhydride reaction with anthracene it adds to the?
Maleic anhydride selectively adds to the center ring of anthracene, rather than either side ring. Reacting at the middle ring leads to an adduct product with two separate benzene rings, each with 6 π electrons.
What is the product of anthracene and maleic anhydride?
In this experiment you will learn how to use the Diels-Alder reaction to form a bridged polycyclic anhydride. Two solids – anthracene and maleic anhydride – will be dissolved in xylene and refluxed. The product 9,10-dihydroanthracene-9,10-α,β-succinic anhydride will be recovered and isolated by vacuum filtration.
Can the Diels-Alder adduct 1 have endo and exo isomers?
The Diels-Alder reaction between cyclopentadiene and maleic anhydride can produce two possible products, the ‘endo’ and the ‘exo’ adducts. This is because although the hydrogens of the maleic anhydride must be cis in the product, there are two possible arrangements where this is true.
What is the adduct in Diels-Alder?
The Diels-Alder reaction is a [4+2] cycloaddition in which a conjugated diene, called the diene, reacts with an alkene group or an alkyne group in a compound, called the dienophile, to give a cycloadduct, called the Diels-Alder adduct.
Which dienophile is used for the furan?
Ernest Z. Furan undergoes Diels-Alder reactions because it can behave as a dienophile.
What type of reaction is Diels-Alder?
In organic chemistry, the Diels–Alder reaction is a chemical reaction between a conjugated diene and a substituted alkene, commonly termed the dienophile, to form a substituted cyclohexene derivative. It is the prototypical example of a pericyclic reaction with a concerted mechanism.
Why is xylene used in Diels-Alder reaction?
Xylene (dimethylbenzene) is used as a high-boiling solvent so that the reaction will work fast enough to complete conveniently. In terms of activation, notice that maleic anhydride is a highly reactive dienophile, due to the presence of two electron-withdrawing carbonyl substituents.
Why is anthracene a diene?
Anthracene, however, is an unusually unreactive diene. This is due to both steric effects, but more importantly because the “diene” is really part of an aromatic ring system and is thus stabilized. This stabilization in the reactant reduces the reactivity (stability/reactivity principle).
What is a Diels-Alder reaction anthracene and maleic anhydride?
The Diels-Alder reaction is a member of a class of reactions called cycloadditions. The reaction involves three π bonds, two from the diene and one from the dienophile in a concerted reaction to form a six-membered ring.
What happens in a Diels-Alder reaction?
The Diels-Alder reaction involves the shift of four pi electrons of the diene and two pi electrons of the dienophile. This reaction is used in the production of vitamin B6. The reverse reaction (also called the retro-Diels-Alder reaction) is used in the production of cyclopentadiene on an industrial scale.
What is the reaction between diene and maleic anhydride?
It is a concerted cyclization reaction which generates an adduct of the starting diene (furan) and dienophile (maleic anhydride) that contains two new C−C bonds. The decomposition of this compound at its melting point of approximately 114∘C simply gives you the original reactants back in a retro Diels-Alder.
Is the reaction between furan and maleic anhydride thermodynamically stable?
BUT THIS REACTION…? But for THIS reaction, of furan with maleic anhydride, as it turns out, the thermodynamic favorability experimentally trumps the kinetic favorability. The exo product is more thermodynamically stable by about 1.9 kcal/mol ( 7.95 kJ/mol ), whereas the endo product is more kinetically stable by about 3.8 kcal/mol.
What is furan-dienophile-anhydride reaction?
It is a concerted cyclization reaction which generates an adduct of the starting diene (furan) and dienophile (maleic anhydride) that contains two new #”C”-“C”# bonds.
Is the endo product for cyclopentadiene + maleic anhydride kinetically favored at room temperature?
So indeed, the endo product for cyclopentadiene + maleic anhydride was kinetically favored (and thermodynamically disfavored) at room temperature. BUT THIS REACTION…? But for THIS reaction, of furan with maleic anhydride, as it turns out, the thermodynamic favorability experimentally trumps the kinetic favorability.