Educational Materials for Organic Chemistry

CONJUGATE ADDITION WITH VARYING EXPERIMENTAL CONDITIONS

Answer the following questions below based on your knowledge of how varying reaction conditions affect product distribution in conjugated dienes.

Question 1:

In the reaction below, Br2 is added to 1,3-butadiene. Which experimental conditions will produce more of 3,4-dibromo-1-butene?

  1. Temp = -15 degrees C and Time = 2 hours
  2. Temp = 25 degrees C and Time = 3 hours

Check if you want question 1 evaluated after you submit your response.

Question 2:

In the reaction below, HBr is added to 1,3-butadiene. Which experimental conditions will produce more of 1-bromo-2-butene?

  1. Temp = -12 degrees C and Time = 1.5 hour
  2. Temp = 50 degrees C and Time = 1 hour

Check if you want question 2 evaluated after you submit your response.

Question 3:

Considering the reaction above, how could you change the experimental conditions to produce more of 3-bromo-1-butene as opposed to 1-bromo-2-butene?
  1. Increase the temperature.
  2. Decrease the temperature.

Check if you want question 3 evaluated after you submit your response.



Clearly, we can see that varying the temperature and time in these reactions affect the product distribution. But, what are the general trends? How can we predict which product will predominate? Click below to find out how product distribution is influenced.

Reaction control of product distribution

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This project was generously supported by the Natural Science Foundation.

Pages developed by Mary Dewan and Dr. Abby Parrill
Department of Chemistry
Michigan State University

These pages may be downloaded and linked freely for academic purposes. Questions, problems, and errors should be sent toparrill@cem.msu.edu.