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The Barrier to Rotation about the Double Bond in Methylenecyclopropane

✍ Scribed by Wolfgang R. Roth; Michael Quast

Publisher
John Wiley and Sons
Year
1998
Tongue
English
Weight
412 KB
Volume
1998
Category
Article
ISSN
1434-193X

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✦ Synopsis

Activation parameters have been determined in the gas phase for the geometrical isomerization of the double bonds in two phenyl-substituted methylenecyclopropanes (2 and 8).

Comparison with the analogous values for three sterically non-restricted styrene derivatives (15, 16 and 17) shows that the enthalpies of activation for the methylenecyclopropanes are lower by 3.7 kcal mol -1 . This value, which is an upper limit to the amount of strain energy released by pyramidalization of the ring carbon atom in the orthogonal diradical

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