Hydrocarbon
1. Concept: Hydrocarbon
Important Points to Remember}
The lower the \(\Delta \mathrm{Hh}\) (heat of hydrogenation), the more stable the alkene is.
- Alkynes and water molecule in presence of mercuric sulphate and dil. \(\mathrm{H}_{2} \mathrm{SO}_{4}\), form carbonyl compounds.
- Terminal alkynes have acidic H-atoms, so they form metal alkynides with Na, ammonical cuprous chloride solution and ammonical silver nitrate solution.
- All \(m\)-directing groups are ring deactivating groups. They are \(:-\mathrm{CHO},-\mathrm{COOH},-\mathrm{NO}_{2},-\mathrm{CN}^{-}-\mathrm{NR}_{3}^{+}\), etc.
D Conformations of n-Butane \(\mathrm{C}_{4} \mathrm{H}_{10}\) :
Order of stability :
Anti \(>\) Gauche \(>\) Skew \(>\) Eclipsed \(>\) Fully Eclipsed
ఎ Hydroboration: Diborane readily reacts with alkenes giving trialkylboranes. Terminal alkenes give primary alkylborane, which can be oxidised by alkaline hydrogen peroxide to primary alcohol.
Hydroxylation: (Cis and Trans)
- With 1\% alkaline \(\mathrm{KMnO} 4(B a e y e r\) reagent):
\(\mathrm{CH}_{3}-\mathrm{CH}=\mathrm{CH}-\mathrm{CH}_{3}+\mathrm{H}_{2} \mathrm{O}+(\mathrm{O})\)
- With per acid (RCOOOH) :
\[
\mathrm{R}-\mathrm{CH}=\mathrm{CH}_{2}+\mathrm{H}-\stackrel{\mathrm{O}}{\mathrm{C}}-\mathrm{O}-\mathrm{OH}
Some important electrophiles used in aromatic substitution are:
