Which alkene is formed from the following pair of alkylidene phosphorane and carbonyl compound?

For the reaction: $CH_2=CH-CH=CH_2 + HBr (1 \text{ eq}) \xrightarrow{80^{\circ}C} P_1 + P_2$ (where $P_1$ is the major product),identify $P_1$.

The organic compound $5-$allylcyclohex$-3-$ene$-1-$ol is reacted with cold,dilute,aqueous solution of $KMnO_4$. The total number of hydroxyl group$(s)$ $(-OH)$ present in the product is

What is formed when $cis-2-butene$ is reacted with cold dilute $KMnO_4$?

Identify product $A$ and product $B$ for the following reaction:

In the following reaction,$P$ gives two products $Q$ and $R$ each in $40 \,\%$ yield. If the reaction is carried out with $420 \,mg$ of $P$,the reaction yields $108.8 \,mg$ of $Q$. The amount of $R$ produced in the reaction is closest to $....\, mg$.