Chemistry Reference
In-Depth Information
Ts
Ts
H
Ts
N
N
N
Ph
3
PA u C l ,
AgSbF
6
+
6.257
6.258
6.256
Scheme 6.104
OMe
Ph
H
IPrAuNTf
2
,
MeOH
MeO
2
C
MeO
2
C
MeO
2
C
MeO
2
C
Ph
6.259
6.260
Scheme 6.105
Cy
2
P
AuCl
Ph
AgSbF
6
MeO
2
C
MeO
2
C
MeO
2
C
MeO
2
C
Ph
H
Ph
LAu
6.261
6.262
MeO
2
C
MeO
2
C
via
6.263
Ph
Scheme 6.106
Cy
2
P
AuCl
AgSbF
6
Ph
Ph
MeO
2
C
MeO
2
C
MeO
2
C
MeO
2
C
6.264
6.265
Scheme 6.107
Ph
Ph
PtCl
4
O
O
Ph
Ph
6.266
6.267
Scheme 6.108
again, depends on subtle structural factors, including alkene geometry (Scheme 6.109): the geraniol-derived
substrate
6.268
gave the simple cycloisomerization product
6.269
, while the isomeric nerol-derived substrate
6.270
gave the double cyclopropanation product
6.271
.
121
The platinum-catalysed cycloisomerization of ene-yne
6.272
to give diene
6.273
was employed in a
synthesis of streptorubin
6.277
(Scheme 6.110).
122
After cyclization, the more electron poor of the two
double bonds was reduced using a palladium-catalysed reduction with a tin hydride reagent. The ketone
6.274
was reduced and the resulting alcohol was excised by the Barton-McCombie method. The resulting
