1. 2-methyl-2-propanol, t -butyl alcohol

1. D. PAVIA CHEM 352 ANSWERS EXAM TWO 1. 2-methyl-2-propanol, t-butyl alcohol cyclopentanol, cyclopentyl alcohol methoxybutane, butyl methyl ether ethoxycyclobutane, cyclobutyl ethyl ether 1-methyl-2-cyclopentenol 1,2-cyclopentanediol 2. a) aprotic solvent, Cl > Br b) acetone c) ethanol 3. a) #1, primary b) #3, iodide leaving group 4. a) #2, tertiary b) #3, iodide leaving group

2. 5. SN2 SN1 (S) SN2 (R) SN2 (S) (S)

3. E2 SN2 (R) (R) SN1 E1 rearranges SN2

4. 6. Cyclopropyl bromide reacts very slowly by either an SN1 or an SN2 mechanism; both require an increase in strain energy. Trigonal planar sp2 bond angles are expected to be 120o -- SN1 ring strain increases this is a bigger discepancy from 60o than the original 109o !!! Tetrahedral sp3 bond angles are expected to be 109o. cyclopropane requires 60o bond angles The SN2 activated complex is also trigonal planar with CCC angles expected to be 120o. SN2

5. 7. a) (R) (R) SOCl2 in pyridine, then NaI in acetone (two inversions, both SN2) b) (R) (S) TsCl in pyridine, then NaI in acetone (retention, inversion (SN2) ) 8. inversion inversion retention

6. 9. via enol

8. 10. (R) (R) (S) (R) (S) racemic

9. 11. (R) (R) (S)

10. 12.