Demercuration polymerization

Oxy-Cope rearrangement. Tertiary 1,5-hexadiene-3-ols undergo oxy-Cope rearrangement at room temperature on treatment with 1 equiv. of mercury(II) trifluoroacetate and subsequent demercuration with sodium borohydride.2 The corresponding secondary alcohols undergo polymerization in the presence of this salt. 

Oxymercuration-demercuration is another method for converting alkenes to alcohols with Markovnikov orientation. Oxymercuration-demercuration works with many alkenes that do not easily undergo direct hydration, and it takes place under milder conditions. No free carbocation is formed, so there is no opportunity for rearrangements or polymerization. 

---