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

B

$HBr,\frac{R}{O}OR$

E

F

G

C

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

t$-$BuOK

E

MeMgBr; $2)H_3{O}^{+}$

$H_2,$ Lindlar's cat.

MeMgBr; $2)H_3{O}^{+}$

J

K

DMP or PCC

TsCl$,$ py

dilute $H_{2}S{O}_4$

I

$LiAl{H}_4$; $2)H_3{O}^{+}$

$LiAl{H}_4$; $2)H_3{O}^{+}$

DMP or PCC

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

D

$HBr$

$H$

dilute $H_{2}S{O}_4$

L

EtMgBr; $2)H_3{O}^{+}$