Question

Which of the given two routes to allyl isopropyl ether is more efficient? Explain.

Answer 1

Williamson's Ether synthesis involves an $S_{N}2$ pathway where the alkoxide ion $(R-O^{-})$ acts as a nucleophile. For obvious reasons, the nucleophile will attack a sterically hindered 2° alkyl halide quite slowly as compared to a primary alkyl halide as we have seen in the $2^{nd}$ case.
Thus, the $2^{nd}$ route is more efficient.