6. Three alkyl halides, each with the formula C,HisBr, have different boiling points. One of the compounds is optically active. Following reaction with Mg in ether, then with water, each compound gives 2,4-dimethylpentane. After the same reaction with D20, a different product is obtained from each compound. Suggest a structure for each of the three alkyl halides. Solution Question #7: a)In order to see the products, we do the reaction, it´s a SN2 reaction (nucleofilic attack by the iodide anion and loss of the leaving group) .It occurs the same way for both molecules. ethyl triflate Ethyl Mesylate b) If we analyze the two anions , we can see this diference Triflate has three fluor atoms, the fluor atom it is known for its highly inductive power, this means that it is very electronegative and thus it has a tendency to attract electrons. If we see the same position in the mesylate, it has a carbon atom with hydrogens (instead of a fluors atoms), the hydrogens present aren´t nearly as electronegative as the fluors, so they will not \"pull\" the electrons with the same force as the fluors atoms. This is why the triflate anion is a much weaker base than the mesylate anion, because the fluors atoms are attracting inductively the electrons and by doing these, these electrons aren´t \"available\" to let the molecule be a stronger base. On the contrary the mesylate anion hasn´t any highly electronegative atoms (compared to the fluors) that attract inductively the electrons, and therefore its electrons are more \"available\" to be a stronger base. c) It will be more reactive to the SN2 reaction, the anion that is most stable (in this case the ethyl triflate produces the anion triflate, this anion is stabilized by the fluor atoms that attract inductively the electrons in the anion). With this, we can say that the fluor atoms are the responsibles of the differences in the reactivity of the reactant molecules and in the anions produced by the SN2 reaction. These fluors atoms are highly atractors of electronic density (electrons) by induction so its presence makes the ethyl triflate \"be\" a better electrophyle and this means that its more \"sensitive\" to the attack of the iodide anion . In the case of the anions products, the same atractive effect of electronic density makes that the charge be less available so it can´t behave as a strong base (triflate anion) compared to the basicity of the mesylate anion. .

1. 6. Three alkyl halides, each with the formula C,HisBr, have different boiling points. One of the
compounds is optically active. Following reaction with Mg in ether, then with water, each
compound gives 2,4-dimethylpentane. After the same reaction with D20, a different product is
obtained from each compound. Suggest a structure for each of the three alkyl halides.
Solution
Question #7:
a)In order to see the products, we do the reaction, it´s a SN2 reaction (nucleofilic attack by the
iodide anion and loss of the leaving group) .It occurs the same way for both molecules.
ethyl triflate
Ethyl Mesylate
b) If we analyze the two anions , we can see this diference
Triflate has three fluor atoms, the fluor atom it is known for its highly inductive power, this
means that it is very electronegative and thus it has a tendency to attract electrons. If we see the
same position in the mesylate, it has a carbon atom with hydrogens (instead of a fluors atoms),
the hydrogens present aren´t nearly as electronegative as the fluors, so they will not "pull" the
electrons with the same force as the fluors atoms.
This is why the triflate anion is a much weaker base than the mesylate anion, because the fluors
atoms are attracting inductively the electrons and by doing these, these electrons aren´t
"available" to let the molecule be a stronger base. On the contrary the mesylate anion hasn´t
any highly electronegative atoms (compared to the fluors) that attract inductively the electrons,
and therefore its electrons are more "available" to be a stronger base.
c) It will be more reactive to the SN2 reaction, the anion that is most stable (in this case the ethyl
triflate produces the anion triflate, this anion is stabilized by the fluor atoms that attract
inductively the electrons in the anion).
With this, we can say that the fluor atoms are the responsibles of the differences in the reactivity
of the reactant molecules and in the anions produced by the SN2 reaction.

2. These fluors atoms are highly atractors of electronic density (electrons) by induction so its
presence makes the ethyl triflate "be" a better electrophyle and this means that its more
"sensitive" to the attack of the iodide anion .
In the case of the anions products, the same atractive effect of electronic density makes that the
charge be less available so it can´t behave as a strong base (triflate anion) compared to the
basicity of the mesylate anion.