Why carbocation is unstable at bridgehead?

Bridge head carbocations are unstable because according to a rule , bridge head carbons cannot form double bonds (Bredt’s rule) . This is because they are out of plane which results in a drastic angle strain between the atoms.

Can alpha carbon be sp2 hybridised?

The carbon atom immediately next to an important functional group in an aliphatic chain is called the “alpha” carbon atom. In CH3-CH=CH-COOH the alpha C atom is sp2-hybridized. If you have a triple bond in place of the double bond, the alpha C atom is sp-hybridized.

Can free radical be formed at bridgehead position?

In addition it has long been known that free radical intermediates at bridgehead positions (which can not invert nor become planar) can form in a number of syn- thetically useful reactions (1, 5).

What is bent Rule explain?

Bent’s rule is that in a molecule, a central atom bonded to multiple groups will hybridise so that orbitals with more s character are directed towards electropositive groups, while orbitals with more p character will be directed towards groups that are more electronegative.

Why are sn1 reactions difficult at bridgehead?

That stabilising effect is not present for the carbon hydrogen bonds in proximity to the bridgehead. Those hydrogens actually point away from the cationic centre, hence overlap is not at all possible. Therefore the charge cannot be stabilised by those bonds.

Is bridgehead free radical stable?

Our results show this bridgehead free radical to be signifi- cantly less stable (the difference in rate of forma- tion is a factor of ten), and, because the radicals are formed directly and no assumptions must be made on two different competing reactions, the perester decompositions are probably better measures of …

What is sp hybridized carbon?

Carbon – sp hybridization. The third possible arrangement for carbon is sp hybridization which occurs when carbon is bound to two other atoms (two double bonds or one single + one triple bond). This hybridization results in a linear arrangement with an angle of 180° between bonds.