Explain why in the synthesis of ether (B) using (A) or A_(1) all the three standard methods for the perparation of ether (B) fail, i.e., I.Intermolecular dehydration of alcohols II.Alkoxy mercuration-demercuration method III. williamson's synthesis Suggest an alternative method for the preparation of (B) by using (A) or (A_(1)) .

Explain why in the synthesis of ether (B) using (A) or A_(1) all the t

1.	Explain why in the synthesis of ether (B) using (A) or A_(1) all the three standard methods for the perparation of ether (B) fail, i.e., I.Intermolecular dehydration of alcohols II.Alkoxy mercuration-demercuration method III. williamson's synthesis Suggest an alternative method for the preparation of (B) by using (A) or (A_(1)) .
Answer» Solution :i.(B) is an unsymmetrical ether, so method (I) cannot be used. Method II. ii. Method II of (a) with (b) would give different ethers, Similarly, method II of (a) with (A) would also give different products. iii. Similarly, method II of `(A_(1))` is not feasible because of the reaction of `Hg^(2+)` with CI of `(A_(1))`. iv.Williamson's SYNTHESIS is also not feasible due to the following reason : 1. 2. 3. Reaction (3) does not take place, but a BRONSTED acid-base reaction occurs GIVING the epoxide. Alternative methods for the synthesis of (B) : i.By nucleophilic addition of `RO^(-)` to ethtne `(HC-=CH)` `HC-=CH` ii. By addition of `Br_(2)` in propanol (SOLVENT) to `(CH_(2)=CH_(2))`