How many of the following compounds on reductive ozonolysis produce formaldehyde $(HCHO)$ as one of the products? The compounds are: $1$-butene,$2$-butene,$2$-methyl-$1$-butene,cyclopentene,cyclobutene,$1$-methylcyclopropene,methylenecyclopropane,$1$-methylcyclopropene (isomer),and cyclohexene.

$2$-methyl-$2$-butene will be represented as:

Identify the product $A$ formed when the following compound is treated with $KMnO_4 / H^+$.

Suppose the following reaction sequence: $CH \equiv CH$ $\xrightarrow[\text{excess}]{NaNH_2 / \text{liq. } NH_3} A$ $\xrightarrow{2 CH_3 - I} B$ $\xrightarrow{H_2 / Pd - BaSO_4, \text{ quinoline}} C$ and $C$ $\xrightarrow{H_2 / Pd - BaSO_4, \text{ quinoline}}$ $\xrightarrow{NaNH_2 / \text{liq. } NH_3} D$. How are $C$ and $D$ related?

Ozonolysis of an organic compound gives formaldehyde as one of the products. This indicates the presence of:

Which of the following reagents can be used to convert propene into propan-$1$-ol?