solvolysis + −OSO 2 CF 3
Vinylic triflate
CC
OSO 2 CF 3
CC+
Vinylic cation Triflate ion
- Alkyl sulfonates provide an indirect method for carrying out nucleophilic
substitution reactions on alcohols.
Step 1
C
R
HR'
OH+ Cl Ts retentio−HCln C
R
HR'
O Ts
Step 2
Nu SN 2 Nu
− C
R
R'H
C
R
HR'
+ O Ts inversion + −O Ts
1) The alcohol is converted to an alkyl sulfonate first and then the alkyl sulfonate is
reacted with a nucleophile.
2) The first step –– sulfonate formation –– proceeds with retention of
configuration because no bonds to the stereocenter are broken.
3) The second step –– if the reaction is SN2 –– proceeds with inversion of
configuration.
4) Allkyl sulfonates undergo all the nucleophilic substitution reactions that alkyl
halides do.
The Chemistry of Alkyl Phosphates
- Alcohols react with phosphoric acid to yield alkyl phosphates:
ROH RO RO
R
ROH RO R
R
P ROH
O
HO OH
OH (−H^2 O)
+
Phosphoric
acid
Alkyl dihydrogen
phosphate
Dialkyl hydrogen
phosphate
P
O
OH
OH (−H^2 O)
P
O
OH
O
Trialkyl
phosphate
(−H 2 O) P
O
O
O
1) Esters of phosphoric acids are important in biochemical reactions (triphosphate
