$7$

$43-$ The major product of the following reaction is: $B{r}_{3}CCC{l}_4$

$44-$ The reaction below is best proceeds through:

a$)S_{N1}1$ mechanism

b$)S{H}_{N2}$ nechanism

$+CH3Br$

c$)$ E ${?}_1$ mechanism

d$)E_2$ mechanism

$45-$The major product of the following reaction is$,C{H}_{3}C-=CHHBr$

a$)C{H}_{3}C{H}_{3}C{H}_{2}Br$

b$)C{H}_{2}CBrC{H}_2$

c$)C{H}_{3}CB{r}_{2}C{H}_3$

d$)C{H}_{3}C{H}_{3}CHB{r}_2$

$46-$ The major product of the following reaction is;

$H{O}_4,H_{3}S{O}_4{H}_{2}S{O}_4$

d$)$

$48.$ What is the steriochemical relationship between the fonowng

A$)$ Diastereoisomers:

B$)$ Enantiomers

C$)$ Identival

D$)$ None of the alove