Q.30-22E

Question

(2E,4Z,6Z,8E)-2,4,6,8-Decatetraene has been cyclized to give 7,8-dimethyl-1,3,5-cyclooctatriene. Predict the manner of ring-closure- conrotatory or disrotatory for both thermal and photochemical reactions, and predict the stereochemistry of the product in each case.

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Answer

To Predict the manner of ring closureconrotatory or disrotatory for both thermal and photochemical reactions, and predict the stereochemistry of the product in each case.

1Cyclization of a tetraene

The reaction which involves in the tetraene cyclization. The electron pair number involved is even and it's under thermal conditions through the ring of conrotatory closure for the yield of cyclic triene with two methyl groups in a trans relationship.

2Reaction will take place in the disrotatory ring

The reaction will take place in the disrotatory ring which yields the cyclic triene with two methyl groups in the cis relationship.

Q.30-21E

Q.30-23E

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