Final answer:
Oxymercuration-demarcation is a two-step process involving the addition of an alcohol in a Markovnikov-selective manner to alkenes. It uses a mercury(II) salt to form a mercurinium ion intermediate, followed by reduction to remove the mercury and give the alcohol product.
Step-by-step explanation:
The student is asking about the oxymercuration-demarcation reaction conditions for Markovnikov's addition of alcohols across the double bond of alkenes. It's important to clarify that oxymercuration-demarcation is a method to hydroxylated alkenes in a Markovnikov selective fashion without rearrangements that are common with direct hydration. This reaction involves first treating the alkene with a mercury(II) salt such as Hg(OAc)2 in water and tetrahydrofuran (THF) to form an intermediate mercurinium ion. This intermediate is then attacked by a water molecule leading to the addition of a hydroxyl group and a mercury-containing group on the more substituted carbon, adhering to Markovnikov's rule. The second step is demercuration where the organomercury intermediate is treated with a reducing agent like sodium borohydride (NaBH4) or thiosulfate (Na2S2O3) to remove the mercury and give the corresponding alcohol product.