Circle the appropriate answer choice; only the major product$/$most efficient method is correct.

$1.$

a$.1.Mg,C{O}_2,$ THF then $H_3{O}^{+}$;$2.H_{3}P{O}_4,$EtOH;$3.C{H}_{3}MgBr,$ THF then $H_3{O}^{+}$

b$.1.Mg,C{O}_2,$ THF then $H_3{O}^{+}$;$2.C{H}_{3}MgBr,$ THF then $H_3{O}^{+}$;$3.H_{3}P{O}_4,$ EtOH

c$.1.Mg,ClC{O}_{2}C{H}_3,$ THF then $H_3{O}^{+}$;$2.H_{3}P{O}_4,$EtOH;$3.C{H}_{3}MgBr,$ THF then $H_3{O}^{+}$

d$.1.NaC{O}_{3}C{H}_3,THF$;$C{H}_{3}MgBr,$ THF then $H_3{O}^{+}$

$2.$

a$.1.BrC{H}_{2}C{O}_{2}Et,Mg,$ THF then $H_3{O}^{+}$;$2.H_{2}S\frac{O_4}{H_2}O,$

b$.C{H}_{3}C{O}_{2}Et,$NaO$\frac{H}{E}$tOH then $H_{2}S{O}_4,H_{2}O$

c$.BrCH2C{O}_{2}Et,$LIOH,$THF,$

d$.1.LiC{H}_{2}C{O}_{2}Et,$ toluene, then $H_{3}O+$;$2.H_{2}S\frac{O_4}{H_2}O$

$3.$

a$.1.$ NaOH, EtOH then $(C{H}_3{)}_{2}CHBr$;$2.H_3{O}^{+},$;$3.xs.Br\frac{2}{N}$aOH then $H_3{O}^{+}$

b$.1.$ LDA, THF$,$ cold then $(C{H}_3{)}_{2}CHBr$;$2.H_3{O}^{+},$;$3.$ xs$.B\frac{r_2}{N}$aOH then $H_3{O}^{+}$

c$.1.$ LDA, THF$,$ cold then $(C{H}_3{)}_{2}CHBr$;$2.H_3{O}^{+},$;$3.A{g}_{2}O,$ LiOH, THF then $H_3{O}^{+}$

d$.1$NaOH FtOH then $(C{H}_2{)}_{2}CHBr$:$2*H_2{O}^{+}.$:$3*H_2{O}_2,H_3{O}^{+}$

$+$

$4.$

a$.1.A{g}_{2}O,$ THF then $H_3{O}^{+}$;$2.H_{3}P{O}_4,NH(C{H}_3{)}_2$;$3.B\frac{r_2}{N}$aOH,$TH\frac{F}{H_2}O$ then $H_3{O}^{+}$

b$.1.SOC{l}_2,$;$2.N{H}_3,THF$;$3.B\frac{r_2}{N}$aOH,$TH\frac{F}{H_2}O$ then $H_3{O}^{+}$

c$.1.A{g}_{2}O,$ THF then $H_3{O}^{+}$;$2.H_{3}P{O}_4,N{H}_3$;$3.B\frac{r_2}{N}$aOH, THF$/H_{2}O$ then $H_3{O}^{+}$

d$.1.H_{2}Cr{O}_4,TH\frac{F}{H_2}O$;$2.H_{3}P{O}_4,N{H}_3$;$3.B\frac{r}{N}$aOH,$TH\frac{F}{H_2}O$ then $H_3{O}^{+}$

$SOC{l}_2,$

PhLi, CuI, THF