Note: Acid-catalyzed addition of H₂O, almost identical to HBr addition, except H₂O is the nucleophile instead of Br-

Caution: Acid-catalyzed H₂O addition occurs through a carbocation intermediate, resulting in carbocation rearrangement issues

Caution: The H₂O addition illustrates an Sn1 mechanism, but then E1 eliminations can compete. Usually this would just give back the starting material anyway, unless a carbocation rearrangement has occured

Note: H₂O adds to alkyne π bonds under acidic conditions similar to alkene addition with respective Markovnikov regioselectivity for terminal alkynes. This results in an enol product that tautomerizes into a more stable keto form

Note: Aqueous acid followup to epoxidation has net effect of anti dihydroxylation

Note: Allylic carbocation intermediates have alternative resonance structures, resulting in the possibility of 1,4 additions beyond the "usual" 1,2 addition

Note: In contrast to 'base driven' epoxide opening like with organometallics, acid-catalyzed epoxide opening prefers the nucleophile (H₂O in this case) to attack the more substituted site based on partial carbocation character