Chemistry Reference
In-Depth Information
CO
2
Me
OH
O
CO
2
Me
Pd(OAc)
2
I
+
Cl
N
Cl
N
1
2
3
BCl
1.8 equiv
2
OH
CO
2
Me
OH
CO
2
Me
Desired product
87% yield
99.5% ee
2.75 kg scale
Cl
N
Cl
N
5
Catalytic CBS reduction
produced
4
5
in 3-10% yields
Figure 16.1 CBS reduction of ketone 3 that was contaminated with trace palladium produced an inseparable mixture of the desired
product 4 and by-product 5. This problem was solved by using a stoichiometric amount of a chiral boron reagent.
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