Biomedical Engineering Reference
In-Depth Information
N
N
Mo
TBSO
O
O
H
H
H
H
O
OTBS
O
46
(30 mol%)
G-II
(10 mol%)
PhMe, 45°C, 14 h
O
OTBS
OTBS
O
O
OTBS
O
O
OTBS
CH
2
Cl
2
/PhMe, 80°C, 14 h
LnRu
84%
Ethylene (1.8 atm)
70%
45
47
48
O
O
O
H
H
H
H
H
H
Ethylene
OH
OTBS
OTBS
O
O
O
O
OTBS
O
O
OTBS
LnRu
50
49
(+)-Amphidinolide V
SCHEME 5.15
Ring-closing alkyne metathesis/enyne cross-metathesis in the total synthesis
of (
þ
)-amphidinolide V by Furstner et al.
underwent cross-metathesis to afford polyunsaturated ester
53
in 60% yield with high
E
/
Z
selectivity (
,
notably bearing multiple olefinic residues, truly illustrate the functional group
tolerance and remarkable selectivity of the metathesis reaction. The cross-metathesis
product
20:1). The heavily functionalized coupling partners
51
and
52
H
and further elaborated to
furnish apoptolidin A. It is interesting to note that the cross-metathesis reaction failed
to take place when allylic alcohol
53
was glycosylated with anomeric sulfoxide
54
was glycosylated (Scheme 5.16) [35].
FR901464, an impressive antitumor agent that regulates the transcription of
oncogenes and tumor suppressor genes, triggered significant interest from the
synthetic community since its disclosure. In Koide's total synthesis of FR901464,
51
Me
Me
Me
Me
Me
Me
HO
HO
O
OEt
Me
Me
O
O
O
OEt
Me
OTBS
51
OTBS
Me
G-II
(9 mol%)
CH
2
Cl
2
, 25°C, 2.5 h
60%
O
O
OMe
H
OMe
H
MeO
O
MeO
O
Me
OMe
Me
OMe
O
O
OTBS
O
O
Me
OTBS
O
O
Me
O
Me
Me
O
Me
Me
OTBS
OTBS
OMe
O
OMe
O
52
53
TESO
Me
TESO
Me
(
E
:
Z
> 20:1)
OTBS
TBSO
S(O)Ph
OH
Me
Me
OTBS
Me
Me
Me
Me
O
HO
O
TBSO
O
O
OEt
MeO
, Tf
2
O
Me
O
O
54
MeO
Me
Me
MeO
O
40%
Me
O
Me
Me
OH
OTBS
Me
O
O
H
OMe
H
OH
H
MeO
O
MeO
O
Me
OMe
OMe
Me
HO
O
OTBS
O
O
Me
O
O
Me
OH
O
Me
Me
O
Me
Me
OTBS
OH
OMe
O
O
OMe
55
TESO
Me
HO
Me
(
+
)-Apoptolidin A
(dr = 10:1)
SCHEME 5.16
Alkene cross-metathesis in the total synthesis of (
þ
)-apoptolidin A by
Crimmins et al.
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