The secondary α-deuterium isotope effect and the mechanism of the diels-alder reaction

✍ Scribed by Stanley Seltzer

• Publisher: Elsevier Science
• Year: 1962
• Tongue: French
• Weight: 203 KB
• Volume: 3
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(00)70492-8

✦ Synopsis

The mechanism of the Diels-Alder reaction has received much attention recently.

2-6

The question of whether formation, isomerization, or decomposition of Dielsdlder adducts occur via a one step 2,5 or a two step3'4'6 mechanism, has been asked most frequently. The use of the secondary adeuterium isotope effect is especially suited to the resolution of this problem since it has already been shown' from the magnitude of this effect, in a similar kinetic problem, that both azo-bis-a-phenylethane and a-phenylethyl-aao-2-propane decompose by breaking both carbon-nitrogen bonds simultaneously rather than decomposing in a two step process. The mechanism of formation of the adduct can be determined, by the Principle of Microscopic Reversibility, from the mechanism of its decomposition. 1 Research performed under the auspices of the U.S. Atomic Energy Commission.