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478 CHAPTER 13 
 
Here is an alternative strategy. An explanation of each 
of the steps (a-d) follows.: 
 
 
 
a. The diol can be made from the trans alkene, by 
converting the alkene into an epoxide and then 
opening under aqueous acidic conditions (or under 
basic conditions). 
b. The alkene can be made from the corresponding 
alcohol, which can be made from the corresponding 
epoxide via a Grignard reaction. 
c. The epoxide can be made from the corresponding 
alkene (called styrene) 
d. The alkene can be made from the alkane via 
bromination, followed by elimination with a strong 
base, such as NaOEt. 
 
The forward synthetic scheme for the second pathway is 
illustrated here: 
OH
OH
1) Br2, h
2) NaOEt
1) PrMgBr
OH
2) H2O
conc. H2SO4, heat
1) RCO3H
2) H3O+
(racemic)
Br
Br2, h
NaOEt
+ En
O
(racemic)
(racemic)
3) RCO3H
4) PrMgBr
5) H2O
6) conc.
7) RCO3H
8) H3O+
heat
H2SO4,
RCO3H
 
 
13.61. There are certainly many acceptable methods 
for achieving the desired transformation. The following 
retrosynthetic analysis represents one such method. An 
explanation of each of the steps (a-e) follows. 
 
 
 
a. The epoxide can be made from the corresponding 
trans alkene. 
b. The trans alkene can be made from the 
corresponding alcohol via a dehydration reaction 
(upon treatment with concentrated sulfuric acid). 
c. The alcohol can be made from the reaction between 
a Grignard reagent (PhMgBr) and an epoxide, 
thereby installing a phenyl group. 
d. The epoxide can be made from the corresponding 
alkene upon treatment with a peroxy acid. 
e. The alkene can be made from the corresponding 
primary alcohol. 
f. The primary alcohol can be made via Grignard 
reaction involving an epoxide. 
 
The forward synthetic scheme is illustrated here: 
 
 
 
 
 
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