Organic Chemistry: Acid-Base Warm up, Reaction Progress Chart, E2 Elimination, IR Spectrum, SN1 and

Acid-Base Warm up

1A) What is the pKA of acetic acid and of phenol (below)?

1B) In the equilibrium below, mark each conjugate acid and its conjugate base.

1C) Clearly show the mechanism (arrows) of deprotonation on each side of the equilibrium.

1D) Which conjugate acid is more stable (i.e. least acidic)? 

1E) Name the compounds below… 1F) ALSO, give an approximate pKA; two items.

2A) On the progress of reaction chart here, label the following:

I. transition state(s)

II. Intermediate.

III. Eact

IV. ?G

V. kinetic product

VI. thermodynamic product

VII. X-axis legend

VIII. Y-axis legend

2A) On the progress of reaction chart here, label the following:

I. transition state(s)

II. Intermediate.

III. Eact

IV. ?G

V. kinetic product

VI. thermodynamic product

VII. X-axis legend

VIII. Y-axis legend

2B) Is the reaction illustrated in the coordinate concerted -OR- stepwise ? (Circle one)

2C) The reaction illustrated in the above coordinate could be which of the following (Circle one):

 {SN1 or E1} -OR- {SN2 or E2} OR- {Protonation} OR- {cannot be determined}

2D) On the progress of reaction chart here, label the following:

I. transition state(s)

II. Eact

III. G

IV. kinetic product

V. thermodynamic product

2E) Is the reaction illustrated in the coordinate:

concerted -OR- stepwise ? (Circle one)

2F) The reaction illustrated in the above coordinate could be which of the following (Circle one):

 {SN1 or E1} -OR- {SN2 or E2} OR- {Protonation} OR- {cannot be determined}

2G) What are the energy units used in the charts above? 

E2 ELIMINATION

3A) Draw a good mechanism (“arrow-pushing”), the transition state, and the product for the E2 elimination reaction below…

3B) The reaction pathway prefers, and is shown as (circle one): gauche syn anti orthogonal

3C) Name the product in the above reaction: __________________________________

--------------------------------

3D) Neatly draw the mechanism and the possible elimination products of the reaction shown below

with tert-butoxide as base (Hint: there are two (2) possibilities; note where protons are):

3E) Indicate the more stable product.

3F) The mechanism in 3D (as shown and described) is (circle one):

SN1 SN2 E1 E2 E1cb cannot be determined

4A) An organic compound has the molecular formula C5H10O3.

Its IR spectrum is shown below. Hint: calculate DBE.

In the Table below, assign 3 or 4 significant IR bands and DRAW the functional group it represents. IR band/signal/frequency Notes and Sketch functional group (Draw each “piece” of the molecule as indicated by the IR assignment.)

4B) Guess/Deduce/Draw a structure or structures that is/are consistent with C4H8O3, and the IR spectrum assignments from above. INDICATE your best guess. [Bonus! for the correct structure.] 

An SN1 and E1 page!

5A) Starting with the alkyl bromide below, center-left, draw the carbocation intermediate twice (2x), once for each mechanism direction in the boxes provided.

5B) Then show good mechanisms (arrow-pushing) and product(s) of both the E1 pathway and the SN1 pathway, respectively. Use hydroxide (-OH) as the nucleophile or the base as needed in the mechanism.

5C) Indicate any stereochemical outcome(s) as needed…

6A) Draw the mechanism of H—Br addition to the alkene below, show the intermediate and how the preferred products form. I.e., draw the first and second step(s) of the addition mechanism.

6B) Draw the two possible (and preferred) products that can form, top or bottom face, from the reaction (include stereochemistry).

6C) Indicate R or S stereochemistry on the products