Q64E - Organic Chemistry (Mcmurry)

Question

Carvone is the major constituent of spearmint oil. What products would you expect from reaction of carvone with the following reagents?

1. ${\left({\mathbf{CH}}_3\right)}_2{\mathbf{Cu}}^{-}{\mathbf{Li}}^{+}$, then ${\mathbf{H}}_3{\mathbf{O}}^{+}$ 
2. ${\mathbf{LiAlH}}_4$, then ${\mathbf{H}}_3{\mathbf{O}}^{+}$
3.  ${\mathbf{CH}}_3{\mathbf{NH}}_2$
4. ${\mathbf{C}}_6{\mathbf{H}}_5\mathbf{MgBr}$, then ${\mathbf{H}}_3{\mathbf{O}}^{+}$
5. ${\mathbf{H}}_2\mathbf{/}\mathbf{Pd}$
   
6. ${\mathbf{CrO}}_3$, ${\mathbf{H}}_3{\mathbf{O}}^{+}$
7. ${\left({\mathbf{C}}_6{\mathbf{H}}_5\right)}_3{\mathbf{P}}^{+}{}^{-}\mathbf{CHCH}_3$
   
8. ${\mathbf{HOCH}}_2{\mathbf{CH}}_2\mathbf{OH}$, HCl

Step-by-Step Solution

Answer

a) 

b)

c)

d)

e)

f) No reaction

g)

h)

Step 1: Reagents used in the reaction of unsaturated ketones

Unsaturated ketones are compounds that contain a ketone group and one double bond, and this double bond is present directly adjacent to the –C=O group. Different reagents reduce the ketone group and double bond, but no reaction is possible if the oxidizing reagent is used.

Step 2: The reaction of carvone with ( CH 3 ) 2 Cu - Li + , then H 3 O +

(a) When the carvone compound is treated with ${\left({\text{CH}}_{\text{3}}\right)}_{\text{2}}{\text{Cu}}^{\text{-}}{\text{Li}}^{\text{+}}$ (Gilman reagent) and then ${\text{H}}_{\text{3}}{\text{O}}^{\text{+}}$, the product is formed by the conjugate addition of the alkyl group. In place of the alkene bond, the addition of the methyl group occurs. The reaction is as shown below

The reaction of carvone with ${\left({\text{CH}}_{\text{3}}\right)}_{\text{2}}{\text{Cu}}^{\text{-}}{\text{Li}}^{\text{+}}$, then ${\text{H}}_{\text{3}}{\text{O}}^{\text{+}}$

Step 3: The reaction of carvone with LiAlH 4 , then H 3 O +

b) When the carvone compound is treated with ${\text{LiAlH}}_{\text{4}}$ (a reducing agent), and ${\text{H}}_{\text{3}}{\text{O}}^{\text{+}}$, the product is formed by converting the ketone group to the alcohol group. The reducing agent reduces ketone to alcohol. The reaction is as shown below.

                                        The reaction of carvone with ${\text{LiAlH}}_{\text{4}}$ , then ${\text{H}}_{\text{3}}{\text{O}}^{\text{+}}$

Step 4: The reaction of carvone with CH 3 NH 2

c) When the carvone compound is treated with ${\text{CH}}_{\text{3}}{\text{NH}}_{\text{2}}$, the product is formed by the conjugate addition of amines. When primary amines are added to $\mathrm{\alpha },\mathrm{\beta }$unsaturated ketones, it results in the formation of $\mathrm{\beta }$-amino ketones. The reaction is as shown below

                             The reaction of carvone with ${\text{CH}}_{\text{3}}{\text{NH}}_{\text{2}}$

Step 5: The reaction of carvone with C 6 H 5 MgBr , then H 3 O +

d) When the carvone compound is treated with ${\text{C}}_{\text{6}}{\text{H}}_{\text{5}}\text{MgBr}$ (Grignard reagent), and ${\text{H}}_{\text{3}}{\text{O}}^{\text{+}}$, the product is formed by 1,2 addition to the carbonyl carbon. The ketone group is converted to –OH, and one ${\text{C}}_{\text{6}}{\text{H}}_{\text{5}}$ is also attached. The reaction is as shown below

                              The reaction of carvone with ${\text{C}}_{\text{6}}{\text{H}}_{\text{5}}\text{MgBr}$ , then ${\text{H}}_{\text{3}}{\text{O}}^{\text{+}}$

Step 6: The reaction of carvone with H 2 / Pd

e) When the carvone compound is treated with ${\text{H}}_{\text{2}}\text{/Pd}$ (a reducing agent), all the alkene bonds are reduced to alkanes. The ketone group remains the same, and this reaction is shown below.

The reaction of carvone with ${\text{H}}_{\text{2}}\text{/Pd}$

Step 7: The reaction of carvone with CrO 3 , H 3 O +

f) When the carvone compound is treated with ${\text{CrO}}_{\text{3}}$, no reaction takes place because ${\text{CrO}}_{\text{3}}$ is an oxidizing agent, and it does not oxidize the ketone group further.

The reaction of carvone with ${\text{CrO}}_{\text{3}}$, ${\text{H}}_{\text{3}}{\text{O}}^{\text{+}}$

Step 8: The reaction of carvone with ( C 6 H 5 ) 3 P + CHCH 3 -

g) When the carvone compound is treated with ${\left({\text{C}}_{\text{6}}{\text{H}}_{\text{5}}\right)}_{\text{3}}{\text{P}}^{\text{+}}{}^{\text{-}}\text{CHCH}_{\text{3}}$ , a Wittig reaction occurs. When ketone compound reacts with ylide, an alkene product is formed, and the reaction is as shown below.

The reaction of carvone with ${\left({\text{C}}_{\text{6}}{\text{H}}_{\text{5}}\right)}_{\text{3}}{\text{P}}^{\text{+}}{}^{\text{-}}\text{CHCH}_{\text{3}}$

Step 9: The reaction of carvone with HOCH 2 CH 2 OH , HCl

h)  When the carvone compound is treated with ${\text{HOCH}}_{\text{2}}{\text{CH}}_{\text{2}}\text{OH}$ and HCl, a 1,4-dioxane-containing product is formed. The ketone group converts into cyclic acetal as shown below.

                The reaction of carvone with ${\text{HOCH}}_{\text{2}}{\text{CH}}_{\text{2}}\text{OH}$,HCl