Question

1. What is the expected product melting point if the bromination of stilbene by PHPB is...

1. What is the expected product melting point if the bromination of stilbene by PHPB is completely
stereospecific (anti addition)?
2. How would the melting point be affected if the reaction is not completely stereospecific and the
dibromide product contains significant amounts of dl-stilbene dibromide, as well as the expected meso
stilbene dibromide? Note the widely differing melting points of the meso and dl isomers.
3. What is the theoretical yield of dibromide product in the bromination reaction?
4. How many products are formed if the bromination reaction proceeds through the bromonium ion
intermediate? How many products are formed if the reaction proceeds through a resonance stabilized
cationic intermediate instead? Can you draw the mechanisms and products? What is the stereochemical
relationship between the products formed in the reaction?

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Answer #1

anayo My p. 120c BY mesomer (to ans) enantiomers M.p 2410 mp. 1140 recemic minture melting point is less than mesocomponand D

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