University:
Brenau University
Course:
CY 201 | Organic Chemistry I
Academic year:

2023
Views:

260

Pages:

3
Author:

peplefamy8b6b

PAL Worksheet SN1 and SN2 Several mechanisms form the core reactions for understanding organic mechanisms. Among these, the most common are SN1, SN2, E1 and E2. In this worksheet, you will focus on the substitution mechanisms. 1. What conditions favor each reaction mechanism listed below? Factor SN1 Substrate SN2 nucleophile leaving group solvent orientation/stereochemistry temperature 2. Rank the following alkyl halide substrates in order of increasing SN2 reaction rate. Now rank the same compounds in order of increasing SN1 reaction rate. 3. Rank the following species in order of their strength as nucleophiles. a. b. CH3S(-) CH3SH H2S HS(-) CH3SH2(+) 4. Assume that both of the following compounds happen to undergo an SN1 reaction. Draw the intermediate for each compound. Which, if either intermediate, is more stable? Why? As a result, which should be formed faster? Therefore, which would be more reactive in an SN1 reaction? 5. For each set of compounds, circle the better leaving group. Explain your choice (a) HO– or H2O (b) CH3SO3– or CF3SO3– (c) F–, Cl–, Br– or I– (d) CH3O– or CH3CO2– 6. How would you be able to tell if the reaction listed below occurred by an SN1 or an SN2 mechanism? (hint—draw out the products of each mechanism) 7. In each of the reactions below, explain what (if anything) is wrong with the proposed synthesis. (note: Tos = Ar-SO2 ) OH CN NaCN a) EtOH TosCl, Py b) NaCl, DMSO OH c) OTos Br CH3 O C ONa Cl O O C CH3 THF 8. Give the expected major products for the following SN2 reactions. Draw the movement of electrons for each reaction using mechanistic arrows. a. b. c. 9. Give the expected major products for the following SN1 reactions. Draw the movement of electrons for each reaction using mechanistic arrows. a. b. c. For further practice: Give the structure of the major product(s) or the reagents necessary to complete each of the following reactions. If necessary, indicate the product stereochemistry. It is recommended that you draw out mechanisms to solidify your understanding of the reactions.