Question

For the first six blanks, please choose only options from the dropdown menus provided below the pictures.

CH3OH ~ ??? Br - în Br OH 2 CH3 F OCH3 < ãnh Look at the given reaction and select the most appropriate answer from the dropdown menus to fill in the analysis. The substrate haloalkane is a primary (unhindered) haloalkane. The nucleophile is a poor nucleophile. And the solvent is protic This means the reaction likely follows a(n) SN2 mechanism(s), which will result in the stereochemistry at the reacting center being inverted • due to anti-periplanar transition state in the mechanism.

Dropdown Menus:

1. methyl, primary (unhindered), primary (hindered), secondary, tertiary

2. poor, weakly basic, strongly basic (hindered), strongly basic (unhindered)

3. protic, aprotic

4. SN2, SN1, E1, E2, SN2 AND E2, SN1 AND E1, No Reaction

5. randomized, inverted, predictable but not inverted, unchanged

6. a planar carbocation intermediate, backside attack transition state, anti-periplanar transition state, other

Answer 1

Answer for first 6 blanks:

1. primary (unhindered)

Reason: Br is attached to primary carbon hence the haloalkane becomes primary and as there is no substitution is present on this carbon it is said to be unhindered.

2. poor

Reason: MeOH is highly polar in nature and when in resonance form or in induction effect it tends to lose the proton very fast. Hence MeO anion acts a good nucleophile but MeOH is a very poor nucleophile.

3. protic

Reason: As MeOH releases proton it is said to be protic solvent. other examples of protic solvents are ethanol, water, butanol, etc.

4. SN2

Reason: For primary haloalkanes in presence of nucleophile SN2 reaction will occur with a cyclic transition state. Similarly, in presence of a strong base elimination will occure with primary haloalkane but MeOH is weak base hence it will not undergo E2 on its own. MeOH is a neutral nucleophile hence will undergo E1 elimination not E2 elimination.

5. inverted

Reason: In Sn2 substitution reaction attack of nucleophile is from rear thus inversion of configuration is achieved.

6. backside attack transition state

Reason: In transition state of SN2 reaction rear attack of nucleophile occurs hence it will be backside attack TS.