Chemistry Reference
In-Depth Information
OMe
MOMO
Me
O
H
O
H
H
Me
NMe
N
O
H
O
CN
O
S
O
NHAlloc
180
3.
t
BuOH
4.
1. DMSO, Tf
2
O
2.
i
Pr
2
NEt
Barton's Base (
5
)
OMe
MOMO
Me
OMe
AllocHN
O
MOMO
Me
H
H
O
Me
S
HO
H
NMe
H
O
Me
N
NMe
O
H
N
O
CN
O
H
O
O
CN
SH
O
182
NHAlloc
181
79%
(5 steps)
Ac
2
O
HO
OMe
AllocHN
OMe
MOMO
Me
NH
HO
Me
O
MeO
O
AcO
S
H
S
H
AcO
H
O
H
Me
O
Me
NMe
NMe
N
N
O
H
O
H
O
CN
O
OH
ecteinascidin 743 (
99
)
Scheme 7.40
Synthesis of ecteinascidin 743 (99)
