Chemistry Reference
In-Depth Information
The major products from similar base treatment of (2
S
,3
S
)- and (2
R
,3
S
)-2-bromo-3-methylpentane can be deduced
as below
Br
Me
Et
Me
Et
Me
Me
Et
(2
S
,3
S
) is the enantiomer;
opposite configuration at each centre
E
it gives the same
product
H
Me
H
Me
H
2
S
,3
S
Br
Me
Et
Et
Me
H
Me
H
Et
it gives the
Z
product
(2
R
,3
S
) is a diastereoisomer;
opposite configuration at C-3
(C-3 is rear chiral centre)
Z
Me
Me
Me
H
2
R
,3
S
Problem 16.07 (level 1; chapters 6, 7 and 8)
In the following four transformations, give detailed mechanisms for the steps indicated.
(a)
MeSO
2
Cl
(MsCl
)
NaOH
H
OH
H
OMs
HO
H
pyridine
H
2
O
(b)
MeI
KOH
H
H
H
heat
H
N
Me
2
N
Me
Me
(c)
O
Mg
O
O
OH
Br
Br
Et
2
O
HO
H
2
SO
4
H
+
H
2
O
OH
HO
(d)
O
O
NH
2
HN
CH
3
HN
CH
3
NH
2
Ac
2
O
CH
3
CO
C
l
KOH
AlCl
3
O
CH
3
O
CH
3
For each sequence, explain why the intermediary steps are advantageous in obtaining the product shown.
