If it helps you, use it. You can also determine the regioselectivity of the reaction based on forming the most stable carbocation. Reactions to memorize - know the reagents and the products, mechanisms nor required. 2.Zn Lindlar's catalyst for the hydrogenation of alkynes Elimination reactions make double-bonds. Mechanism will be discussed later.
Resonance stabilizes carbocations.
Be able to draw resonance structures. Does addition reactions like alkenes, only it can do it twice. This carbanion can then be a nucleophile in substitution reactions. Chapter Five Aromatic compounds are an important class of organic compounds, of which benzene is the simplest example. In general, aromatic compounds contain six-membered rings that have three double bonds so that the conjugation extends all the way around the ring.