Propose an efficient synthesis for the following transformation:

The transformation above can be performed with some reagent or combination of the reagents listed below. Give the necessary reagent$($s$)$ in the correct order, as a string of letters $($without spaces or punctuation, such as "EBF"$).$ If there is more than one correct solution, provide just one answer.

A

NaOEt

D

MeMgBr

$H_3{O}^{+}$

G

$B{r}_2$

B

t$-$BuOK

E

$N{a}_{2}C{r}_2{O}_7,H_{2}S{O}_4,H_{2}O$

C

PCC$,C{H}_{2}C{l}_2$

conc. $H_{2}S{O}_4,$ heat

I

$B{H}_3*THF$

$H_2{O}_2,H_{2}O$