Question

Complete the mechanism for the reaction by adding curved arrows. The reagents chosen for the transformation are: 1) Hg(OAc)2, THF, H₂O and 2) NaBH4, OH⁻. (The acetate ion is a spectator throughout.)

Answer 1

The mechanism of the reaction involves the formation of a mercurinium ion in the presence of mercury(II) acetate and the reduction by sodium borohydride in a basic medium to yield an alcohol.

Step-by-step explanation:

The question involves understanding and executing a reaction mechanism where mercury(II) acetate and sodium borohydride are the reagents in the transformation of an organic compound. The mercury(II) acetate is typically involved in an electrophilic addition to a double bond via the mercurinium ion intermediate. Subsequent reduction by sodium borohydride (NaBH4) in basic medium provides the corresponding alcohol as the product. Adding curved arrows to the mechanism would entail showing the movement of electron pairs during the formation of the mercurinium ion and its subsequent reduction.

During the first step, we would observe an electron pair from the double bond attacking the mercury center of Hg(OAc)2, forming a cyclic mercurinium ion. The presence of water would facilitate the attack on the mercurinium ion to form the alcohol. In the second step, the NaBH4 donates hydride ions, which attack the mercury-activated alkene to replace the mercury with hydrogen, ultimately yielding the alcohol.