The two product in the given reaction are formed after [1, 7] sigmatropic rearrangement, one due to hydrogen migration and the other to deuterium migration. It should be represented the configuration of product by replacing the A and B with appropriate atoms (H or D) Concept introduction: In a sigmatropic reaction “ one new sigma-bond is formed as another breaks.” Sigma tropic rearrangement reactions are designated with digits. For example a [1, 3] sigma tropic rearrangement describe a reaction in which the residue migrates from position 1 to position 3 Woodward –Hoffmann rules are the set of rules used to vindicate or predict certain aspects of the stereo chemical outcome and activation energy of pericyclic reactions. Woodward – Hoffmann rules for sigma tropic rearrangement reactions are listed below S u m o f t h e n u m b e r o f b o n d s i n t h e r e a c t i n g s y t e m s o f b o t h r e a g e n t s Reaction conditions Allowed mode of bond formation Even number Thermal Antarafacial Photochemical Suprafacial Odd number Thermal Suprafacial Photochemical Antarafacial Migration of carbon and hydrogen will occur in a sigmatropic rearrangement reaction. Migration of hydrogen in suprafacial and antarafacial rearrangement can be represented as follows, Carbon migrating with one lobe of its p orbital interacting Carbon migrating with both lobe of its p orbital interacting

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Chapter 28, Problem 35P

Interpretation Introduction

Interpretation:

The two product in the given reaction are formed after [1, 7] sigmatropic rearrangement, one due to hydrogen migration and the other to deuterium migration. It should be represented the configuration of product by replacing the A and B with appropriate atoms (H or D)

Concept introduction:

In a sigmatropic reaction “ one new sigma-bond is formed as another breaks.”

Sigma tropic rearrangement reactions are designated with digits. For example a [1, 3] sigma tropic rearrangement describe a reaction in which the residue migrates from position 1 to position 3

Woodward –Hoffmann rules are the set of rules used to vindicate or predict certain aspects of the stereo chemical outcome and activation energy of pericyclic reactions.

Woodward – Hoffmann rules for sigma tropic rearrangement reactions are listed below

Sum of the number of bonds in the reacting sytems of both reagents Reaction conditionsAllowed mode of bond formationEven numberThermalAntarafacialPhotochemicalSuprafacialOdd numberThermalSuprafacialPhotochemicalAntarafacial

Migration of carbon and hydrogen will occur in a sigmatropic rearrangement reaction. Migration of hydrogen in suprafacial and antarafacial rearrangement can be represented as follows,

Carbon migrating with one lobe of its p orbital interacting

Carbon migrating with both lobe of its p orbital interacting

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