O
Br
CHO
NI
O
O
N
H
N B
O
O
Ts
n-Bu
O
Br
COOEt
OH
O
O
COOEt
O
OH
COOEt
O
O
COOEt
O
NH 2
O
O
O
N
H
BnHN
EtOOC
N
EtOOC
O
H
O
O
N
H
I
Bn
O
O
O
N
H
NsHN
EtOOC
O
O
N
H
H 2 N
EtOOC
O
H
HO
O
N
H
N
EtOOC
O
Bn
O
CHO
Br
OSiMe 3
OEt
t-BuOK
O
O
O
O Rh
Rh
O
O
O
O
NO 2
SO 2 NH 2
N
H
H
OH
OH
O
N
O
H
EtOOC
N
OH
N
O
O 3 S
O
R
1
O
OR
2
OH
OR
3
O
O
N
O
H
O
N
H
NH 2
H 2 N
O
N
i-Pr
H
O
OMe
MeOH
+
Cat. 218
CH 2 Cl 2 , - 78
o
C
Cat. 218
67%
219
220 (dr = 5:1; ee = 72%)
218 :
221
222
75%
223
1) Cl 3 C(O)NCO
CH 2 Cl 2 , 20
o
C
2) Al 2 O 3 /CH 2 Cl 2
95 %
1) Rh 2 (esp) 2
PhI(OAc) 2
MgO
2) NsNH 2
DMF
75 %
225
89%
229
Banyaside A, R
1 = COC 5 H 11
R
2 = CONH 2 , R
3 = H
Banyaside B, R
1 = R
2 = H
R
3 = COC 5 H 11
Rh 2 (esp) 2 :
NsNH 2 :
224
K 2 CO 3
PhSH
MeCN
20
o
C
91%
226
PhCHO
NaBH 3 CN
92%
hn/CH 2 Cl 2
227
SmI 2
THF
0 - 20
o
C
82%
228
1) Mn(dpm) 3
PhSiH 3 /O 2
EtOH, 20
o
C
2) H 2 , Pd/C
66%
Mn(dpm) 3 :
tris(dipivaloylmethanato)manganese(III)
Scheme 39 Carreira et al.’s synthesis of the core element of banyasides
176
A.J. Moreno-Vargas and P. Vogel