102
H. Zhu et al.
412 (periconiasin G)
NH
O
O
O
(R)-citronellal
1) (CH 2 OH) 2 , (±)-CSA,
HC(OEt ) 3 (99 %)
2) OsO 4 (1.2 mol%), 2,4,6-collidine,
H 2 O 2 , KMnO 4
3) NaIO 4 , H 2 O/MeOH (10:1),
(44% over two steps)
O
O
CO 2 H
1) BnBr, K 2 CO 3 , acetone,
130°C (Mw), 8 min (86 %)
2) AcOH (80% in H 2 O),
10°C (Mw), 6 min (quant.)
O
CO 2 Bn
CrCl 2 , CHI 3 , (77%, (E)/(Z) = 11:1)
1) aq. NaOH (90%)
2) CDI, Et 3 N, (96%)
N
O
N
PdCl 2 (dppf).CH 2 Cl 2 , KOH,
(4.7:1) (75%, (E)/(Z) = 8:1)
CO 2 Bn
(HO) 2 B
CO 2 Bn
I
Bz
N
O
O
NBz
O
O
NBz
O
NH
O
O
LiHMDS, THF (65%)
1) LiHMDS, PhSeBr
(93%)
2) m-CPBA, H 2 O 2 ,
CHCl 3
1) sealed tube, 100°C
(44% over two steps,
endo/exo: 3:1 )
2) aq. NaOH, MeOH,
(64% of and 32% of
20)
E1
E2
E3
A4
E5
E6
E7
E8
E9
(14R)
Scheme 6 Synthesis of periconiasin G
103 (cytochalasin B)
HN
O
HO
OH
O
O
HN
O OAc
OH
26 (L-696,474)
Fig. 23 Structures of cytochalasin B and L-696,474