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246 CHAPTER 8 
 
(d) The reagents indicate a hydroboration-oxidation. 
The net result of this two-step process is the anti-
Markovnikov addition of H and OH across the  bond. 
That is, the OH group is installed at the less-substituted 
position, while the H is installed at the more substituted 
position. In this case, only one chiral center is created. 
Since syn addition can take place from either face of the 
alkene with equal likelihood, we expect a pair of 
enantiomers, as shown: 
 
 
 
(e) The reagents indicate a hydroboration-oxidation. 
The net result of this two-step process is the anti-
Markovnikov addition of H and OH across the  bond. 
That is, the OH group is installed at the less-substituted 
position, while the H is installed at the more substituted 
position. In this case, no chiral centers are created, so 
the requirement for syn addition is irrelevant. 
 
 
(f) The reagents indicate a hydroboration-oxidation. The 
net result of this two-step process is the anti-
Markovnikov addition of H and OH across the  bond. 
That is, the OH group is installed at the less-substituted 
position, while the H is installed at the more substituted 
position. In this case, two chiral centers are created. 
Therefore, the stereochemical requirement for syn 
addition determines that the H and OH are added on the 
same face of the alkene, giving the following products: 
 
 
 
 
8.17. The problem statement indicates that this is a hydroboration-oxidation sequence, the net result of which is an anti-
Markovnikov addition of H and OH across the  bond. That is, the OH group is installed at the less-substituted 
position, while the H is installed at the more substituted position. In this case, two chiral centers are created. Therefore, 
the stereochemical requirement for syn addition determines that the H and OH are added on the same face of the 
alkene, giving the products shown. Note that the highlighted methyl group creates steric hindrance on the top face of 
the ring, so the major product arises from hydroboration from the bottom face: 
 
Major Minor( )- -Pinene
C
H3C
CH3
H
H
H
CH3
H3C
H
OH
H
CH3
CH3
H3C
OH
H
CH3
H
+1) B2H6
2) H2O2, NaOH
 
 
8.18. 
(a) The reagents indicate a catalytic hydrogenation 
process, so we expect the addition of H and H across the 
alkene. In this case, the product does not have a chiral 
center, so stereochemistry is not a relevant consideration. 
 
H2
Ni
 
 
(b) The reagents indicate a catalytic hydrogenation 
process, so we expect the addition of H and H across the 
alkene. In this case, the product does not have a chiral 
center, so stereochemistry is not a relevant consideration. 
 
 
 
(c) The reagents indicate a catalytic hydrogenation 
process, so we expect the addition of H and H across the 
alkene. In this case, the product has one chiral center, so 
we expect both possible enantiomers (syn addition can 
occur from either face of the  bond). 
 
 
 
(d) The reagents indicate a catalytic hydrogenation 
process, so we expect the addition of H and H across the 
alkene. In this case, the product does not have a chiral 
center, so stereochemistry is not a relevant consideration. 
 
 
 
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