In hydroboration–oxidation, borane adds to the double bond with the boron atom attaching to the sp² carbon carrying more hydrogen atoms, contrary to Markovnikov’s rule. The reaction yields excellent alcohol formation.

Hydroboration–oxidation involves the reaction of alkenes with diborane to form trialkyl boranes, which are then oxidized to alcohols by hydrogen peroxide in the presence of aqueous sodium hydroxide. This process contradicts Markovnikov’s rule as the boron atom attaches to the ...

Reactions with carboxylic acids and acid anhydrides require concentrated sulfuric acid, while reactions with acid chlorides use a base like pyridine. Acetylation, as seen in the production of aspirin from salicylic acid, involves introducing an acetyl group (CH₃CO) into alcohols ...

Electron-withdrawing groups enhance the acidic strength of phenol, with a more pronounced effect at ortho and para positions. Effective delocalization of negative charge in the phenoxide ion occurs when the substituent is at these positions.

Charge delocalization, illustrated by resonance structures I-V, increases the stability of phenoxide ions. The phenol molecule is less stable due to charge separation in its resonance structures, favoring the ionization of phenol.