From: Guido de Silvestri (Inprodos$##$Tutopia.com)
Date: Mon Mar 11 2002 - 13:35:42 EST
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Dear Uno:
Excuse me for a little late answer to your question about the Diels-Alder reaction.
Firstly, let me tell you that the dienic synthesis for a six members ring, was one of the must important contribution to the inks and dyes chemistry. All of us, have to thank to Otto Diels and Kurt Alder for those investigations, realized in the early 50's.
In those kind of reactions, it takes part a double conjugated link substance (a dienic compound) and a unsaturated substance (a dienophylic compound), producing an adduct. The double link from the dienophylic compound, get activated with an electrons attract group prescience, even when ethylene could take part in Diels-Alder reactions.
The must of the dienophylic substances have an ab double link with regard to an activator group, such as carbonylic, carboxylic or nitrile group. For example, in the reaction between butadiene and acroleyne, it achieves a quantitative yield to the adduct, in one hour, at 100°C
When the dienic and dienophylic substances are acyclic, the adduct has a six member ring. Otherwise, if the dienophylic substance is cyclic and the dienic compound is acyclic, a two ring adduct is obtained.
Within energetic conditions, you can achieve the reaction between two moles of butadiene with one mole of benzoquinone (may be the answer you are asking for)
If the dienic substance is cyclic and the dienophylic is not, the reaction achieves to a cyclic compound with a bridge.
In the case of the two of the reagents are cyclic in both, the reaction yields to very complex ringer like structures.
Now to finish, the Diels-Alder synthesis great value, stems from it enables to prepare many cyclic compounds that could not be easily prepared by no other way. In other words, it has the simplicity attractive.
I hope that I was able to dispel your doubts.
Best regards from Colombia,
Guido De Silvestri.
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----- Original Message -----
From: "Uno Mäeorg" <uno$##$chem.ut.ee>
To: "Multiple recipients of list orglist" <orglist$##$dq.fct.unl.pt>
Sent: Tuesday, February 19, 2002 7:28 AM
Subject: ORGLIST: Diels-Alder reaction
:
:
: Dear colleagues,
:
: I'm looking for information about the Diels-Alder reaction with
: anthraquinone. Can somebody help me?
:
:
: Uno Maeorg
:
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