Progress in the Chemistry of Cytochalasans
91
HN
O O
HN
O O
HN
O O
N
H
N
H
N
H
A
B
C
H
N
O
O
H
N
O
O
MycB
B6 (myceliothermophin E )
221 (prochaetoglobosin I) (endo)
diastereo-221 (exo)
in vitro
B4
B5
NCOPh
O
O
Ph
100°C 5 h
52%
NCOPh
O
O
Ph
NCOPh
O
O
Ph
B1
3
B
2
B
B2:B3 = 52:48
Scheme 3 Previous studies on Diels–Alder (DA) cycloadditions. a A chemical synthesis procedure
to achieve intramolecular DA reactions. b The retro-Diels–Alder reaction of prochaetoglobosin I
(221). c MycB was proven to be a Diels–Alderase to form decalin through in vitro characterization.
d A gene knockout experiment of pyiF afforded multiple linear shunt products B10–B17, giving
indirect evidence that PyiF is the Diels–Alderase in the biosynthesis of pyrichalasin H (164)
91
HN
O O
HN
O O
HN
O O
N
H
N
H
N
H
A
B
C
H
N
O
O
H
N
O
O
MycB
B6 (myceliothermophin E )
221 (prochaetoglobosin I) (endo)
diastereo-221 (exo)
in vitro
B4
B5
NCOPh
O
O
Ph
100°C 5 h
52%
NCOPh
O
O
Ph
NCOPh
O
O
Ph
B1
3
B
2
B
B2:B3 = 52:48
Scheme 3 Previous studies on Diels–Alder (DA) cycloadditions. a A chemical synthesis procedure
to achieve intramolecular DA reactions. b The retro-Diels–Alder reaction of prochaetoglobosin I
(221). c MycB was proven to be a Diels–Alderase to form decalin through in vitro characterization.
d A gene knockout experiment of pyiF afforded multiple linear shunt products B10–B17, giving
indirect evidence that PyiF is the Diels–Alderase in the biosynthesis of pyrichalasin H (164)