You met ways of making 1,2-difunctionalized compounds when we first talked about two-group dis-
connections, and we used ari epoxide as an aZ synthon. Epoxides are, of course, also 1,2-functional-
ized, and in fact this is often the key to making 1,2-functionalized compounds: use something with
the 1,2 relationship already in place. You saw lots of examples of this type of strategy earlier in this
chapter. Perhaps the simplest approach is electrophilic addition to alkenes. If the alkene is made by a
Wittig reaction, the disconnection is(铲entually) between
the target molecule. This example shows dih川roxylation
the two functionalized carbon atoms in
as the electrophilic addition but there is
also epoxidation, bromination, and bromination in water to give Br and OH as the functional
groups.
ketone.