THE DIELS ALDER REACTION, A USEFUL SYNTHETIC METHODOLOGY

R.C.Jagessar* et.al.

The Diels Alder reaction is a useful synthetic methodology to make six membered rings with diverse functions. It involves the reaction of a diene with a dienophile under thermal conditions. The reaction is stereospecific. Reaction of anthracene with succinic anhydride in xylene, yielded compound (1), 9,10 dihydroanthracene-9,10-endo-a, b-succinic anhydride in yield of 10.5% as a white solid, whereas reaction of anthracene with cyclohexane yielded compound (2), 9,10-endo--a, b-cyclohexane as a white gray solid in yield of 28%. Under standard conditions as expected, the reaction of anthracene with a non dienophile maleic anhydride was negative. UV/Vis spectral studies as the only means of characterization available here, indicates lmax at 330 nm of absorbance 0.16 with a shoulder at 370 nm. There is also an intense band in the region 310-350 nm. For compound (2), UV/Vis spectral studies indicates the presence of two peaks. The feasibility of a Diels Alder reaction is predicted using Molecular Orbital Theory. The Diels Alder reaction has many applications. These include the synthesis of pesticides, flame retardants, agriculture fungicide such as Captan.