Carbocation stability order? so basically it's between primary benzylic carbocation which is known to be stable (benzlic) and secondary carbocation which is allylic... which is also stablized by resonance, i know that usually benzylic is more stable than allylic but when they are same degree.. here its different...
any help?
The tropylium carbocation (the one on the right) is more stable than the primary benzylic carbocation because it is not only resonance stabilised but also quasi-aromatic (which means that the charge is a part of the aromaticity) which greatly increases the stability of the cation. In contrast, the benzylic carbocation is aromatic but the positive charge is not a part of the aromaticity so it is not stabilised that much.
Hope it helps!