What reagent is used to convert (-)-Carvone to (-)-Dihydrocarvone through hydrogenation?

Question

ScanSolve AI Tutor · Accepted Answer

This reaction involves the reduction of two carbon-carbon double bonds in the reactant.

Identify the reactant and product.
The reactant is (-)-Carvone. It contains an $\alpha,\beta$ -unsaturated ketone (a double bond conjugated with a carbonyl group) and an exocyclic alkene (an isopropenyl group).
The product is (-)-Dihydrocarvone. In the product, both the $\alpha,\beta$ -unsaturated double bond and the exocyclic alkene have been reduced to single bonds. The ketone remains, but the conjugated double bond is gone. The isopropenyl group has been reduced to an isopropyl group.
Determine the type of transformation.
The conversion involves the addition of hydrogen across carbon-carbon double bonds. This is a hydrogenation reaction, which is a type of reduction.
Select appropriate reagents for hydrogenation.
Catalytic hydrogenation is the standard method for reducing carbon-carbon double bonds. This typically involves hydrogen gas ( $\text{H}_2$ ) in the presence of a metal catalyst. Common catalysts include palladium on carbon ( $\text{Pd/C}$ ), platinum oxide ( $\text{PtO}_2$ ), or Raney nickel ( $\text{Ni}$ ). These conditions will reduce both the alkene and the $\alpha,\beta$ -unsaturated ketone.

The reagent for the conversion of (-)-Carvone to (-)-Dihydrocarvone is:
$\boxed{\text{H}_2, \text{Pd/C}}$
(Other suitable catalysts like $\text{PtO}_2$ or $\text{Ni}$ could also be used.)

Answer