Page 909 - Advanced Organic Chemistry Part B - Reactions & Synthesis

of this stereoelectronic effect. In both cyclic and acyclic systems, the rearrangement 885
takes place with retention of configuration at the migrating group.
SECTION 10.1
Reactions and
CH 3
CH 3 SO 2 O CH 3
Rearrangement
H + H –H + H Involving Carbocation
Intermediates
CH 3 CH 3 CH 3
PhCH 2 O CH 3 O PhCH 2 O O PhCH 2 O CH 3 H O
H CH 3H
O O O
8 9
(mixture of double
bond isomers
Ref. 64
Similarly, 10 gives 11 by antiperiplanar migration.

O – O
ArSO O O O O
2
CH 3 CH 3 O O
O O
AcO 10 AcO AcO CH 3 11
Ref. 65

Rearrangement of diol monosulfonates can also be done using Lewis acids. These
conditions lead to inversion of configuration at the migration terminus, as would be
implied by a concerted mechanism. 66

CH SO 3 R
3
R
2 5 2
CH 3 R (C H ) AlCl CH R
OH 3
O
Triethylaluminum is also effective in catalyzing rearrangement of monosulfonate with
high stereospecificity. The reactions are believed to proceed through a cyclic TS. 67

R 2 R 1
OH R R 2
R 2 Et Al O R
3
R
R 1 O Al O
R 1
CH
OSO 2 3 S
O O
CH
3
The reactants can be prepared by chelation-controlled addition of organometallic
reagents to -(1-ethoxyethoxy)methyl ketones. Selective sulfonylation occurs at the

64
M. Ando, A. Akahane, H. Yamaoka, and K. Takase, J. Org. Chem., 47, 3909 (1982).
65 C. H. Heathcock, E. G. Del Mar, and S. L. Graham, J. Am. Chem. Soc., 104, 1907 (1982).
66 G. Tsuchihashi, K. Tomooka, and K. Suzuki, Tetrahedron Lett., 25, 4253 (1984).
67
K. Suzuki, E. Katayama, and G. Tsuchihashi, Tetrahedron Lett., 24, 4997 (1983); K. Suzuki,
E. Katayama, and G. Tsuchihashi, Tetrahedron Lett., 25, 1817 (1984); T. Shinohara and K. Suzuki,
Synthesis, 141 (2003).