13. Alcohols and Carbonyl Compounds

Predict the products you would expect from the reaction of NaBH₄ with the following compounds. You may assume that these reactions take place in methanol as the solvent.

(f)

Compounds containing deuterium (D = ²H) are useful for kinetic studies and metabolic studies with new pharmaceuticals. One way to introduce deuterium is by using the reagent LiAlD₄, equivalent in reactivity to LiAlH₄. Show how to make these deuterium-labeled compounds, using LiAlD₄ and D₂O as your sources of deuterium, and any non-deuterated starting materials you wish.

(b) CH₃CD₂OH

Show how you would synthesize each compound, starting with an ester containing no more than eight carbon atoms. Any other necessary reagents may be used.

(i) HO–(CH₂)₈–OH

Show how you would accomplish the following synthetic conversions. You may use any additional reagents and solvents you need.

(b)

Show the reagents required to form the primary alcohol in each of the following reactions.

a. Show the reagents required to form the primary alcohol in each of the following reactions.

What products are obtained from the reaction of the following compounds with LiAlH₄ followed by treatment with dilute acid?

a. ethyl butanoate

b. benzoic acid

Show how you would synthesize the following alcohol by reducing appropriate carbonyl compound.

c. 2-methylhexan-3-ol

Predict the product of the following reductions.

(a)

For each synthesis, start with bromocyclohexane and predict the products. Assume that an excess of each reactant is added so that all possible reactions that can happen will happen.

(b)

The esters shown differ only by the alkoxy group.

(i) Predict the product(s) obtained when these react with DIBAl-H.

(ii) Based on your answer, in a sequence like this, would there ever be a need to convert from one ester to another?

(a)

Predict the product of the following reaction sequences.

(c)

Draw the structure of two esters that will be reduced to propanol and butanol by LiAlH₄ (followed by addition of aqueous acid).

Sodium triacetoxyborohydride, NaBH(OAc)₃, is a mild reducing agent that reduces aldehydes much more quickly than ketones. It can be used to reduce aldehydes in the presence of ketones, such as in the following reaction:

(a) Draw a complete Lewis structure for sodium triacetoxyborohydride.

Draw the organic products you would expect to isolate from the following reactions (after hydrolysis).

(k)

(l)