13. Alcohols and Carbonyl Compounds

Suggest carbonyl compounds and reducing agents that might be used to form the following alcohols.

(e)

(f)

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)

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

(k)

(l)

Suggest the most appropriate method for each of the following laboratory syntheses. In each case, suggest both a chromium reagent and a chromium-free reagent.

(f) 1-methylcyclohexanol → 2-methylcyclohexanone (several steps)

Show how you would make each compound, beginning with an alcohol of your choice.

(g)

(h)

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.

(c) CH₃CD₂OD

Both NaBH₄ and NaBD₄ are commercially available, and D₂O is common and inexpensive. Show how you would synthesize the following labeled compounds, starting with butan-2-one.

(a)

Suggest the most appropriate reagent for each synthesis, and explain your choice.

(c)

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 products of the following reactions. Indicate whether each reaction is an oxidation or a reduction.

a.

b.

c.

Propose a mechanism for the following reaction:

Predict the product of the following reaction sequences.

(c)

Show how you would synthesize the following compounds from the appropriate carboxylic acids or acid derivatives.

How can the following compounds be prepared from the given starting materials?

b.