FUNCTIONAL GROUP INTERCONVERSIONS 119
Functional Group Interconversions
C&S Chapter 3 #1; 2; 4a,b, e; 5a, b, d; 6a,b,c,d; 8
1 sulfonates
2 halides
3 nitriles
4 azides
5 amines
6 esters and lactones
7 amides and lactams
Sulfonate Esters
- reaction of an alcohols (1° or 2°) with a sulfonyl chloride
R OH R O S
O
O
R' CH3
CF3
CH3
R'SO2Cl
sulfonate ester
R'= mesylate
triflate
tosylate
- sulfonate esters are very good leaving groups. Elimination is often a
competing side reaction
Halides- halides are good leaving groups with the order of reactivity in SN2 reactions
being I>Br>Cl. Halides are less reactive than sulfonate esters, however
elimination as a competing side reaction is also reduced.
- sulfonate esters can be converted to halides with the sodium halide in acetone
at reflux. Chlorides are also converted to either bromides or iodides in the same
fashion (Finkelstein Reaction).
R O S
O
O
R' R X
X-X= Cl, Br, I
R Cl R I
NaI, acetone
reflux
- conversion of hydroxyl groups to halides: Organic Reactions 1983, 29, 1
R OH R X
- R-OH to R-Cl
- SOCl2
- Ph3P, CCl4
- Ph3P, Cl2
- Ph3P, Cl3CCOCCl3
