Organic Reactions Volume 4 - Sciencemadness Dot Org

2 ORGANIC REACTIONS
NATURE OF THE REACTION
The Diels-Alder reaction (diene synthesis) consists in the addition
of a compound containing a double or triple bond (usually activated by
additional unsaturation in the apposition) to the 1,4-positions of a
conjugated diene system, with the formation of a six-membered hydroaromatic
ring. The following additions of various diene systems to
dienophiles are typical examples of the Diels-Alder reaction.
XH2
^CH2 X CH ^ CHO
•V . V\ . rTv^
j, + x / . > ^ ^
+ CH
W
Diene Dienophilo Adduct
A noteworthy feature of the Diels-Alder reaction is the great variety
of the compounds which may serve as the dienophile. With a few exceptions,
the compounds that have been employed as dienophiles fall into
one of the following categories.
1. CH2=CHA.
A « CHO, CO2H, CO2CH3, CO2C2H5, COCl, COCH3, COC6H5, CN, NO2,
C6H5, CH2OH, CH2X, CH2NH2, CH2CN, CH2CO2H, CH2NCS,
OCOCH3, SC6H4CH3, SO2R, X, H.