Chemistry Reference
In-Depth Information
CH
3
CN
n
-BuLi or LDA
CO
CN
CN
CH
2
CN, -78
°C
O
Fe(CO)
3
(OC)
3
Fe
(OC)
3
Fe
1
1
1
0
.
5
1
5
4
Me
I
RT
CN
CN
CN
CN
H
+
O
(OC)
3
Fe
Me
Fe(CO)
3
10.55
10.59
10.58
10.57
O
CN
10.56
Scheme 10.16
The ability of the iron tricarbonyl group to both protect and activate a diene can be exploited.
20
Treatment
of the
4
-tropone complex
10.21
with an organozinc reagent resulted in Michael addition to the uncomplexed
alkene; after manipulation of the carbonyl group, generation of the enolate
10.62
resulted in intramolec-
ular nucleophilic attack onto the diene complex giving interesting bicyclic structures after CO insertion
(Scheme 10.17). The stereochemical role of the Fe(CO)
3
moiety is apparent throughout this scheme. Both
O
O
M
CO
2
Et
CO
2
Et
(OC)
3
Fe
(OC)
3
Fe
M = Cu(CN)ZnI
1
.
1
0
.
TBSO
1. NaBH
4
2. TBSOTf, 2,6-lutidine
LDA
CO
2
Et
(OC)
3
Fe
10.61
TBSO
OHC
TBSO
1. CO
2. H
+
CO
2
Et
CO
2
Et
(OC)
3
Fe
1
6
1
6
3
Scheme 10.17
