The tri-n-Methane Rearrangements

The light-induced rearrangement reactions of trivinyl methanes to give divinyl cyclopropane and vinyl cyclopentene derivatives are known as the tri-n-methane rearrangements. The reaction involves both singlet and triplet excited states. For 

Suggest a mechanistic rationalization for each of the following reactions and mention the major product when more than one product is formed 

Predict the stmcture(s) of the principal product(s) formed in the foUowing reactions  

Coyle JD (1986) Introduction to organic photochemistry. Wiley, New York 

Kagan J (1993) Organic photochemistry, principles and applications. Academic Press, New York 

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