Which of the following correctly describes the relative nucleophilicities of methoxide and tert-butoxide? tert-Butoxide is more nucleophilic because it is more basic. Methoxide is more nucleophilic because the nucleophilicity of tert-butoxide is diminished by steric effects. These alkoxides have essentially the same nucleophilicities since the negative charge in both is localized on an oxygen atom. tert-Butoxide is more nucleophilic because tert-butanol has a larger acid dissociation value than methanol. tert-Butoxide is more nucleophilic because it contains three methyl groups which increase the charge on its oxygen by donating electron density.

Rank the following reactions in order of increasing nucleophile strength: Cl-, H2O, CH3-, H2S, HS-, I-

15. Which of the following correctly describes the relative nucleophilicities of methoxide and tert- butoxide? A) These alkoxides have essentially the same nucleophilicities since the negative charge in both is localized on an oxygen atom. B) Methoxide is more nucleophilic because the nucleophilicity of tert-butoxide is diminished by steric effects. C) tert-Butoxide is more nucleophilic because it contains three methyl groups which increase the charge on its oxygen by donating electron density. D) tert-Butoxide is more nucleophilic because it is more basic. E) none of the above 16. Rank the species below in order of increasing nucleophilicity in protic solvents: CH3CO2-, CH3S-, HO-, H2O. Answer: A. H2O

Benzyl bromide (C6H5CH2Br) reacts rapidly with CH3OH to afford benzyl methyl ether (C6H5CH2OCH3). Draw a stepwise mechanism for the reaction, and explain why this 1° alkyl halide reacts rapidly with a weak nucleophile under conditions that favor an SN1 mechanism. Would you expect the para-substituted benzylic halides CH3OC6H4CH2Br and O2NC6H4CH2Br to each be more or less reactive than benzyl bromide in this reaction? Explain your reasoning.