Which of the following is a very good ethylating agent for converting `R-OH` into `R-Oet`?

Options

A. `Et-(3)overset(+)(O)bar(B)F_(4)`
B. `Et_(2)O`
C. `Et_(2)overset(+)(O)-bar(B)F_(3)`
D. `C_(2)H_(5)OH`

Answer

A

Explanation

Trialyloxonium fluoroborates, `R_(3)overset(+)(O)bar(B)F_(2)` are powerful alkylating reagents for nucleophilic substrates such as alcohol.
`RO-H overset(Et_(3)overset(+)(Obar(B)F_(4)))rarr RO - Et`