Ketones are prepared by

$1$-Phenylethanol can be prepared by the reaction of benzaldehyde with the product obtained in the reaction between

In the reaction $CH_3CN + 2H \underset{\text{Ether}}{}$ ${\xrightarrow{HCl}} X$ $\xrightarrow{\text{Boiling } H_2O} Y$; the product $Y$ is

$C_6H_5CH_3$ $\xrightarrow{CrO_2Cl_2} A$ $\xrightarrow{H_2O} B$
The functional group present in $B$ and the name of the reaction are:

Explain the method of preparation of aldehydes and ketones from Grignard reagents with suitable examples.

$A$ man has been asked to synthesize the molecule shown in the image. He thought of preparing the molecule using an aldol condensation reaction. He found a few cyclic alkenes in his laboratory. He thought of performing an ozonolysis reaction on an alkene to produce a dicarbonyl compound,followed by an aldol reaction to prepare "$x$". Predict the suitable alkene that can lead to the formation of "$x$".