Rigby, JH, Kirova-Snover, M., Tetrahedron Lett. 1997, 38, 8153-8156.

I
1.Zn,THF,Me 3 SiCl
Cr(CO) 3
150 °C
CO 2 Et
Cr(CO) 3
BF 4
-
2. CuCN, LiCl,
-78°Cto0°C
CO 2 Et
dioxane
CO 2 Et
1. LDA, THF-HMPA,
MeI
2. DIBAL, THF, 0 °C
1. mCPBA, CH 2 Cl 2 ,0°C
2. H 2 ,Pd(C),MeOH
(separation of epimers)
CO 2 Et
3. TsCl, py, 0 °C
4. LiEt 3 BH,THF,0°C
3. MeO 2 CNSO 2 NEt 3 ,
PhH, 60 °C
Tl(ONO 2 ) 3
MeOH, rt
OMe
OMe
1. H 3 O +
2. NaBH 4 ,EtOH,0°C
3. o-NO 2 C 6 H 4 SeCN, Bu 3 P, THF
4. H 2 O 2 ,THF,rt
Rigby, J.H., Kirova-Snover, M., Tetrahedron Lett. 1997, 38, 8153-8156.

O
1. LDA, TMSCl, THF
O
1.
N
TBDMSOTf,
CH 2 Cl 2 ,-78°C
TBDMSO
1. NaH, CS 2 then MeI
O
O
O
O
O
2. Pd(OAc) 2 ,CH 3 CN
O
O
2.
THF, -78 °C
MgBr
HO
O
O
2. nBu 4 NF
S
O
S
O
O
O
Ph
NH 2
N
MeOH
Ph
Ph
N
N
Ph
O
O
1. nBu 3 SnH, AIBN,
syringe pump, 20h
O
+
O
S
O
S
S
O
S
2. TsOH, MeOH
H
H
15% 45%
1. MeLi
2. SOCl 2 ,py
3. TsOH, CH 2 Cl 2
H
Lee, H.-Y., Lee, S., Kim, D., Kim, B.K., Bahn, J.S., Kim, S., Tetrahedron Lett. 1998, 39, 7713-7716.