Chemistry Reference
In-Depth Information
8.38
As described, a synthesis of disparlure is:
8.39
a.
By analogy with crown ethers, it is the ether oxygens of nonactin and
monensin that are expected to bind to the metal cations. The carboxylate and
alcohol oxygens in monensin, and the ester oxygens in nonactin, might also
be involved.
b.
Nonactin is cyclic and probably has a cavity size that is only conducive to
complexation of sodium cation. Monensin is acyclic, more flexible than
nonactin, and probably can fold in a manner that accommodates larger
potassium ions.
8.40
Excess HBr would convert 1,4-dioxane to:
8.41
Since the product has only two carbons and the starting material has four carbons,
two groups of two carbons must be separated by an ether oxygen:
C
C
O
C
C
The remaining two oxygens (C
4
H
10
O
3
) must be at the ends of the chain. The desired
structure is
HO
CH
2
CH
2
O
CH
2
CH
2
OH
and the equation for the reaction with HBr is
HOC H
2
CH
2
OCH
2
CH
2
OH
4 HBr
2 Br CH
2
CH
2
Br
+
3 H
2
O
+
In this step, the ether is cleaved, and the alcohol functions are also converted to alkyl
halides.
