Progress in the Chemistry of Cytochalasans
109
1) LiHMDS,
PhSeCl;
2) NaOH
3) H 2 O 2
61%, 3 steps
HN
O
O
1) 1,3-dimesityl-1Himidazol-3-ium chloride,
n-BuLi, PMBOH, 70%
2) DDQ, 82%
HN
O O
HO
404 (periconiasin A)
MeOH,
150°C,
6%
HN
O
OH
HO
409 (periconiasin E)
DMP,
85%
HN
O O
O
406 (periconiasin C)
L-selectride,
82%
HN
O O
HO
405 (periconiasin B)
MeOH, 150°C,
59%
HN
O
O
OH
408 (periconiasin D)
1) DMP
2) Me 4 NBH(OAc) 3
62%, 2 steps
HN
O
OH
HO
17-epi-periconiasin E
TsOH,
80%
17
G7
G8
Scheme 11 Collective synthesis of periconiasins A–E
398 (aspergillin PZ)
NH
O O
O
OH
O
OTBS
OTBDPS
X
TBSO
SnCl 4
Prins/pinacol
O
TBDPSO
O
Scheme 12 Overman’s synthesis of aspergillin PZ