Chemistry Reference
In-Depth Information
H
H
H
H
OPiv
OPiv
MeO
2
C
MeO
2
C
O
O
O
O
Pd(OAc)
2
[
o
-(MeO)
2
C
6
H
3
]
3
P
OTES
OTES
O
O
HO
O
HO
O
OTBS
OTBS
11.282
11.281
CO
2
Me
MeO
2
C
H
H
OPiv
MeO
2
C
O
O
OH
O
1. Ph
3
PAuCl, AgSbF
6
2. Piv
2
O, DMAP
3. TBAF
H
O
O
OH
CO
2
Me
11.283
Scheme 11.94
H
OTBDPS
OTBDPS
R
O
O
O
O
O
O
O
PMB
PMB
CpRu(NCMe)
3
PF
6
11.284
O
O
11.286
Me
3
Si
OH
R = SiMe
3
NBS
OTBS
OTBS
R = Br
11.285
Scheme 11.95
The fact that cycloisomerization and related reactions provide a mild method for carbon-carbon bond
formation, with the need for strong acids and bases, is further demonstrated by the fact that another of these
reactions was used earlier in the same synthesis to combine alkyne
11.285
with alkene
11.284
to give the
pyran
11.286
(Scheme 11.95).
References
1. (a) Lautens, M.; Klute, W.; Tam, W.
Chem. Rev.
1996
,
96
, 49; (b) Schore, N. E.
Chem. Rev.
1988
,
88
, 1081.
2. Wender, P. A.; Jenkins, T. E.; Suzuki, S.
J. Am. Chem. Soc.
1995
,
117
, 1843.
3. (a) Wender, P. A.; Jenkins, T. E.
J. Am. Chem. Soc.
1989
,
111
, 6432; (b) Wender, P. A.; Smith, T. E.
J. Org. Chem.
1995
,
60
, 2962.
