Q58E - Organic Chemistry (Mcmurry)

Question

Predict the products of the reaction of (1) phenylacetaldehyde and (2) acetophenone with the following reagents:

1. ${\mathbf{NaBH}}_{\mathbf{4}}$, then  ${\mathbf{H}}_{\mathbf{3}}{\mathbf{O}}^{\mathbf{+}}$
2.   Dess-Martin reagent
3. ${\mathbf{NH}}_{\mathbf{2}}\mathbf{OH}$, HCl catalyst
4. ${\mathbf{CH}}_{\mathbf{3}}\mathbf{MgBr}$, then ${\mathbf{H}}_{\mathbf{3}}{\mathbf{O}}^{\mathbf{+}}$
5. $\mathbf{2}{\mathbf{CH}}_{\mathbf{3}}\mathbf{OH}$, HCl catalyst
6. ${\mathbf{H}}_{\mathbf{2}}{\mathbf{NNH}}_{\mathbf{2}}$, KOH
7. ${\left({\mathbf{C}}_{\mathbf{6}}{\mathbf{H}}_{\mathbf{5}}\right)}_{\mathbf{3}}\mathbf{P}\mathbf{=}{\mathbf{CH}}_{\mathbf{2}}$
   
8.  HCN, KCN

Step-by-Step Solution

Answer

a. The reaction of phenylacetaldehyde,

The reaction of acetophenone,

b. The reaction of phenylacetaldehyde,

The reaction of acetophenone,

c. The reaction of phenylacetaldehyde,

The reaction of acetophenone,

d. The reaction of phenylacetaldehyde,

The reaction of acetophenone,

e. The reaction of phenylacetaldehyde,

The reaction of acetophenone,

f. The reaction of phenylacetaldehyde,

The reaction of acetophenone,

g. The reaction of phenylacetaldehyde,

The reaction of acetophenone,

h. The reaction of phenylacetaldehyde,

The reaction of acetophenone,

Reactions of aldehydes and ketones

The reactions of aldehydes and ketones involve various reactions like the formation of alcohols (${\mathbf{1}}^{\mathbf{o}}\mathbf{,}{\mathbf{2}}^{\mathbf{o}}\mathbf{,}{\mathbf{3}}^{\mathbf{o}}$), formation of cyanohydrins, formation of hemiacetals, and reduction by ${\mathbf{NaBH}}_{\mathbf{4}}$. These all involve nucleophiles, bond formation, and bond breaking occurs in these reactions.

The product of the reaction of (1) phenylacetaldehyde and (2) acetophenone with NaBH 4 , then H 3 O +

a. The reaction of phenylacetaldehyde with ${\text{NaBH}}_{\text{4}}$ and then ${\text{H}}_{\text{3}}{\text{O}}^{\text{ + }}$ yields primary alcohol. The aldehyde group (-CHO) reduces to alcohol (${\text{ - CH}}_{\text{2}}\text{OH}$) when it is treated with a reducing agent (${\text{NaBH}}_{\text{4}}$).

                        Reaction of Phenylacetaldehyde

The reaction of acetophenone with ${\text{NaBH}}_{\text{4}}$ and then ${\text{H}}_{\text{3}}{\text{O}}^{\text{ + }}$ yields secondary alcohol. The ${\text{ - COCH}}_{\text{3}}$ group reduces to $\text{ - CH}\left(\text{OH}\right){\text{CH}}_{\text{3}}$ when treated with a reducing agent (${\text{NaBH}}_{\text{4}}$).

                            Reaction of acetophenone

The product of the reaction of (1) phenylacetaldehyde and (2) acetophenone with the Dess-Martin reagent

b. The reaction of phenylacetaldehyde with Dess-Martin yields phenylacetic acid. The aldehyde       group (-CHO) oxidizes to carboxylic acid (-COOH) when it is treated with an oxidizing agent (Dess-Martin).

                            Reaction of Phenylacetaldehyde

The reaction of acetophenone with Dess-Martin gives no reaction. The ${\text{ - COCH}}_{\text{3}}$ group does not further oxidize to any other group.

                                               Reaction of acetophenone

The product of the reaction of (1) phenylacetaldehyde and (2) acetophenone with NH 2 OH , HCl catalyst

c. The reaction of phenylacetaldehyde with ${\text{NH}}_{\text{2}}\text{OH}$ and HCl catalyst yields the (N)-hydroxy-2-phenylethanimine.

                                Reaction of Phenylacetaldehyde

The reaction of acetophenone with ${\text{NH}}_{\text{2}}\text{OH}$ and HCl catalyst gives the following product shown in the reaction.

                                      Reaction of acetophenone

The product of the reaction of (1) phenylacetaldehyde and (2) acetophenone with CH 3 MgBr . then H 3 O +

d. The reaction of phenylacetaldehyde with Grignard reagent yields a secondary alcohol product. The Grignard reaction with aldehyde gives secondary alcohol.

                        

                                Reaction of Phenylacetaldehyde

The reaction of acetophenone with Grignard reagent gives a tertiary alcohol product. We know, the Grignard reaction of ketone gives tertiary alcohol.

                       Reaction of acetophenone

The product of the reaction of (1) phenylacetaldehyde and (2) acetophenone with 2 CH 3 OH , HCl catalyst

e. The reaction of phenylacetaldehyde with ${\text{2CH}}_{\text{3}}\text{OH}$ and HCl catalyst gives acetal as a product. The reaction is as follows,

 

                                  Reaction of Phenylacetaldehyde

The reaction of acetophenone with ${\text{2CH}}_{\text{3}}\text{OH}$ and HCl catalyst gives the following product shown in the reaction below.

                                 Reaction of acetophenone

The product of the reaction of (1) phenylacetaldehyde and (2) acetophenone with H 2 NNH 2 , KOH

f. The Wolff-Kishner reaction occurs when phenylacetaldehyde reacts with ${\text{H}}_{\text{2}}{\text{NNH}}_{\text{2}}$, and KOH, the product formed, is an alkane. In this type of reaction, an aldehyde or ketone converts into an alkane.

 

                               Reaction of Phenylacetaldehyde

The Wolff-Kishner reaction occurs when acetophenone reacts with ${\text{H}}_{\text{2}}{\text{NNH}}_{\text{2}}$, and KOH, and the product obtained is an alkane. The ketone or aldehyde group is converted into an alkane.

                                      Reaction of acetophenone

The product of the reaction of (1) phenylacetaldehyde and (2) acetophenone with C 6 H 5 3 P = CH 2

g. When phenylacetaldehyde reacts with ${\left({\text{C}}_{\text{6}}{\text{H}}_{\text{5}}\right)}_{\text{3}}{\text{P = CH}}_{\text{2}}$, the product formed is an alkene.

                                  Reaction of Phenylacetaldehyde

When acetophenone reacts with ${\left({\text{C}}_{\text{6}}{\text{H}}_{\text{5}}\right)}_{\text{3}}{\text{P = CH}}_{\text{2}}$, the ketone group is converted into an alkene and is shown as follows,

                                       Reaction of acetophenone

The product of the reaction of (1) phenylacetaldehyde and (2) acetophenone with HCN, KCN

h. When phenylacetaldehyde reacts with HCN and KCN, a cyanohydrin is formed as a product

 

                             Reaction of Phenylacetaldehyde

When acetophenone reacts with HCN and KCN, the product formed again is cyanohydrin.

                                 Reaction of acetophenone