1,2,6-heptatriene Cope rearrangement

Much experimental and theoretical work has been performed with the two allenes 1,2,6-heptatriene (32) and 1,2,6,7-octatetraene (34). Thermal isomerization of 32 leads to 3-methylene-l,5-hexadiene (346), a process that at first sight looks like a typical Cope rearrangement. However, trapping experiments with either oxygen or sulfur dioxide have shown that at least half of the rearrangement passes through the diradical 345 (Scheme 5.52) [144],... 

Exercise 21-21 The Cope rearrangement is a type of sigmatropic rearrangement that occurs with 1,5-dienes. An example is the rearrangement of 3-methyl-1,5-hexa-diene to 1,5-heptatriene ... 

S.3.4.2 Cope Rearrangement of 1,2,6-Heptatriene Roth examined the Cope rearrangement of 1,2,6-heptatriene 40 to 3-methylenehexa-l,5-diene 41 and was able to trap a diradical intermediate with oxygen. He proposed that about half of... 

Figure 4 Schematic representation of the Cope rearrangement of (left) 1,2,6-heptatriene via (middle) 2-methylenecyclohexane-l, 4-diyl to (right) 3-methylene-1,5-hexa-diene...

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