Page 913 - Advanced Organic Chemistry Part B - Reactions & Synthesis

Scheme 10.3. Rearrangements Promoted by Adjacent Heteroatoms 889
A. Pinacol-type rearrangements SECTION 10.1
1 a Reactions and
OH H 2 SO 4 O
Rearrangement
Ph
COH Involving Carbocation
Ph Ph 99% Intermediates
Ph
2 b
H SO 4
2
O
CH
O 2
69–81%
OH
3 c OSO Ar
HO 2 O
H
K + – OC(CH )
3 3
H
CH 3 CH 3 H CH
CH 3 CH 3
3 CH
3 85%
4 d O
CH SO O H CH 3
3
2
OH CH 3
pyridine CH
CH 3 3
Et N
3
CH O C 91%
3
2
CH O C
2
3
5 e
CF SO CH 2 CH H SO HO CH 3
3
3
CH 3 3 2 4 CH 3
O CF CH OH, H O O
2
3
2
CH 3 80°C CH 3 100%
O O
6 f
CC H NO
OH O 2 6 4 2 O
O CC H NO
HC(OCH 3 ) 3 2 6 4 2
OH 97%
SnCl , 20 mol %
4
7 g
OH 1) CH 3 SO 2 Cl O
H OH
2) (C H ) AlCl 37%
2 5 2
8 h
OTMS
O TiCl 4 CH 3 OH
CH 3
OTIPS CH OTIPS
CH CH 3 3 CH
3
OTBDMS 3 OTBDMS 96%
CH O
9 i
O OCH 3 1) CH SO Cl CH OCH 3
3
2
3
CH 3 CH 3 pyridine HO CH 3
OH
2) DiBAlH 63%
(Continued)