Which SN2 reaction in aqueous acetone solution occurs most rapidly?
a. OH- + (CH3)3C-Br > (CH3)3C-OH + Br-
b. OH- + CH3-CH2-Br > CH3CH2OH + Br-
c. OH- + CH3-Br > CH3OH + Br-
d. OH- + (CH3)2CH-Br > (CH3)2CH-OH + Br-
e. OH- + (CH3)3C-CH2-Br > (CH3)3C-CH2-OH + Br-
Could you please give me the "why" as well as the correct answer? Thank you.
a. OH- + (CH3)3C-Br > (CH3)3C-OH + Br-
b. OH- + CH3-CH2-Br > CH3CH2OH + Br-
c. OH- + CH3-Br > CH3OH + Br-
d. OH- + (CH3)2CH-Br > (CH3)2CH-OH + Br-
e. OH- + (CH3)3C-CH2-Br > (CH3)3C-CH2-OH + Br-
Could you please give me the "why" as well as the correct answer? Thank you.
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c) The reason is that carbon is an electron donor. Since the electrons of hydroxide must attack the carbon opposite the bromine, any addition of electron or electron density will impede the reaction. A methyl group doesn't have any carbons to donate electron density, hence it will react the fastest.