Question

5. (a) The following is a substitution reaction using a sulfonium ion, which has a sulfur-based leaving group, rather than an alkyl halide. Four different nucleophiles were used in the substitution reaction and their rates were measured Rationalize the trend in reaction rates and indicate the dominant mechanism in each case Nu SPh2 Ph OH SH Rate 3.9 3.8 74 257 (b) (R)-2-Bromooctane was stirred with excess sodium iodide in acetone at room temperature for 2 days. Write an equation for this reaction. Further experimentation showed the rate of the reaction was dependent on the concentration of both the alkyl halide and the iodide nucleophile, yet the product was a racemic mixture. Rationalize this result.

Answer 1