Chemistry Reference
In-Depth Information
O
O
Ph
(Ph
3
P)
2
PdCl
2
, CO,
(H
2
N)C=S, Et
2
NH, DBU
I
Ph
AcO
HO
Ph
O
4.15
4.16
Scheme 4.10
MeO
BrZn
PEPPSI, CO,
LiBr, PPh
3
I
OMe
+
MeO
OMe
OMe
4.17
4.18
MeO
O
MeO
O
1. BBr
3
2. Cs
2
CO
3
OMe
OMe
MeO
OMe
MeO
O
OMe
OMe
4.19
4.20
Scheme 4.11
MeN
NMe
O
t
-Bu
N
+
I
OTIPS
Me
3
Sn
4.21
4.22
Pd
2
dba
3
, Ph
3
As
CO (50 psi), LiCl
NMP
N
O
t
-Bu
MeN
NMe
H
N
O
N
OTIPS
H
O
O
H
4.23
4.24
Scheme 4.12
lithium enolate allows the carbonylative-coupling - Nazarov - hydrogenation sequence to be repeated to give
the tricycle
4.32
via enone
4.31
. Finally, a Wittig reaction yielded the natural product
4.25
. Quite different
syntheses of capnellene can be found in Chapter 5, Scheme 5.40 and Chapter 8, Schemes 8.58-8.60.
A carbonylative coupling of a vinyl derivative was employed in a synthesis of cylindricine C
4.33
(Scheme
4.14).
14
In this case, the double Michael acceptor ability of the product was exploited to generate the tricyclic
product, following protecting group manipulation and installation of nitrogen in the form of azide. Another
synthesis of this molecule can be found in Scheme 11.89.
