Question

14 multiple choice 2 points how many vinylic and allylic hydrogens are there in hexa - 1,4 - diene? 5 vinylic, 4 allylic 6 vinylic, 3 allylic 5 vinylic, 5 allylic 3 vinylic, 2 allylic previous

Explanation:

Step1: Draw the structure of hexa - 1,4 - diene

$$CH_2=CH-CH_2-CH=CH-CH_3$$

Step2: Identify vinylic hydrogens

Vinylic hydrogens are attached to \(sp^2\) hybridized carbon atoms in a double bond. In \(CH_2 = CH - CH_2 - CH = CH - CH_3\), the \(CH_2=\) and \(=CH-\) groups contribute vinylic hydrogens. There are \(5\) vinylic hydrogens (\(2\) from \(CH_2=\) at the first double bond, \(1\) from \(=CH-\) between \(CH_2\) groups, and \(2\) from \(=CH-\) at the second double bond).

Step3: Identify allylic hydrogens

Allylic hydrogens are attached to \(sp^3\) hybridized carbon atoms adjacent to a \(C = C\) double bond. In \(CH_2=CH - CH_2 - CH = CH - CH_3\), the \(CH_2\) groups adjacent to the double bonds contribute allylic hydrogens. There are \(4\) allylic hydrogens (\(2\) from the \(CH_2\) between the two double bonds and \(2\) from the \(CH_2\) adjacent to the terminal double bond).

Answer:

5 vinylic, 4 allylic