Question

I answered 4.a as C- 15-crown-5, is that correct? If not, what is and please explain how you got the answer. Trying to figure 4.a 4.b and 5 out....

4. Identify the missing reagent needed to carry out the following transformation. NaF Benzene Br A) 12-crown-5 B) 12-crown-4 C) 15-crown-5 D) 18-crown-6 E) none of these 4. Provide the reagents necessary to prepare the following compound using alkoxymercuration . demercuration. Answer: 5. Explain why long-term storage of ethers can be dangerous. Two sentences max!

Answer 1

4. Yes, your answer is correct. The reagent used for the reaction is NaF. 15-Crown-4 ether has high affinity towards sodium cation. Hence 15-Crown-4 ether is suitable for the reaction.

4. Oxymercuration & Demercuration

1. Hg(OAc2 но 2 NaBH

Oxymecuration is a electrophilic addition reaction. In first step mercuration takes place using mercuric acetate in corresponding alcohol solvent to give the addition product of acetoxymercury group and alccoxy group across the double bond. Later demercuration takes place in presence of reducing agent sodium borohydride to yield the desired product.

5. Ethers can become more dangerous with prolonged storage because they tend to form explosive peroxides. Exposure to light and air enhance the formation of the peroxides.