Nidulaxanthone
A
is
a
dimeric,
dihydroxanthone
natural
product
which
was
isolated
in
2020
from
Aspergillus
sp.
Structur-ally,
the
compound
features
an
unprecedented
heptacyclic
6/6/6/6/6/6/6
ring
system
unusual
for
xanthone
dimers.
Biosynthetically,
nidulaxanthone
originates
monomer
nidulalin
via
stereoselective
Diels-Alder
dimeri-zation.
To
expedite
synthesis
of
and
study
proposed
dimerization,
we
developed
methodology
involving
use
allyl
triflate
chromone
ester
activation
followed
by
vinylogous
addition
to
rapidly
forge
scaffold
four-step
sequence
also
ketone
desaturation
using
Bobbitt’s
oxoammonium
salt.
The
asymmetric
achieved
acylative
kinetic
resolution
(AKR)
chiral,
racemic
2H-nidulalin
A.
Dimerization
en-antioenriched
solvent-free,
thermolytic
conditions.
Computational
studies
have
been
conducted
probe
both
(4+2)
dimerization
events.
Organic Letters,
Journal Year:
2025,
Volume and Issue:
unknown
Published: Feb. 19, 2025
A
synthetic
route
to
the
highly
functionalized
tetracyclic
core
framework
of
daphlongamine
B
is
described.
Key
features
strategy
involve
an
oxidative
dearomatization-induced
[4+2]
cycloaddition,
a
di-π-methane
rearrangement,
and
ring-closing
metathesis
reaction.
Our
approach
enables
reliable
construction
fully
elaborated
precursor,
which,
in
turn,
provides
valuable
functional
handles
for
further
elaboration
target
molecule.
Journal of the American Chemical Society,
Journal Year:
2025,
Volume and Issue:
unknown
Published: March 10, 2025
The
family
of
Cephalotaxus
diterpenoids
represents
a
captivating
class
natural
products
that
are
significant
interest
from
both
structural
and
biological
perspectives
within
our
community.
Here
we
wish
to
report
15-step,
enantioselective
total
synthesis
the
diterpenoid
fortalpinoid
Q.
Our
approach
highlights
(1)
Jacobsen's
catalytic
Claisen
rearrangement
enabled
single-step
formation
two
vicinal
stereogenic
centers,
including
an
all-carbon
quaternary
center;
(2)
mild,
oxoammonium
salt
(TEMPO+BF4-)-promoted
dehydrative
Nazarov
cyclization
swiftly
forged
crucial
cyclopentadiene
moiety
via
unfunctionalized
tertiary
divinyl
carbinol
(TDC)
substrate;
(3)
facile
aldol-lactonization
cascade
ultimately
resolved
last
obstacle
in
synthesis.
The Journal of Organic Chemistry,
Journal Year:
2025,
Volume and Issue:
unknown
Published: April 28, 2025
The
TEMPO+
(2,2,6,6-tetramethylpiperidine-N-oxyl
cation)
is
a
versatile
chemical
species
commonly
known
as
an
oxidizing
reagent.
Nevertheless,
its
capability
to
act
Lewis
acid
has
been
recently
revealed.
Here,
we
report
TEMPO+-promoted
oxa-Ferrier
rearrangement
of
glycals
chiral
α,β-unsaturated
δ-lactones
using
sodium
chlorite
(NaClO2)
cheap
and
environmentally
friendly
Since
the
vinylic
oxocarbenium
intermediate
trapped
by
ion
form
carbonyl
group,
name
this
reaction
"Oxa-Ferrier
rearrangement".
Accordingly,
suitable
for
various
O-acetylated,
O-benzoylated,
O-benzylated
glycals,
providing
corresponding
in
moderate
good
yield.
Additionally,
synthetic
utility
methodology
was
applied
synthesis
confirmation
absolute
configuration
passifetilactones
B
C.
Cell Reports Physical Science,
Journal Year:
2024,
Volume and Issue:
5(9), P. 102141 - 102141
Published: Aug. 6, 2024
Fusicoccane
diterpenoids,
originating
from
fungi,
plants,
and
bacteria,
constitute
a
diverse
natural
product
family
featuring
5-8-5
tricyclic
framework.
They
were
restricted
to
plant
physiology
in
the
past.
However,
fusicoccanes
are
presently
at
forefront
of
biomedicine
indispensable
for
probing
14-3-3
protein-protein
interactions
(PPIs).
The
need
material
supply
scaffold
diversification
encouraged
their
study
by
synthetic
community.
This
review
highlights
total
works
on
fusicoccane
diterpenoids
published
last
5
years.
Key
transformations
including
ring-closing
metathesis,
metal-catalyzed
cross-coupling,
carbocyclization
markedly
enhanced
efficiency
versatility.
Recently
identified
biosynthetic
inspired
innovative
chemoenzymatic
strategies.
Investigation
into
functional
aspects
should
be
future
direction
realize
therapeutic
potential
as
general
PPI
modulators.
Organic Letters,
Journal Year:
2023,
Volume and Issue:
25(27), P. 4956 - 4961
Published: June 29, 2023
A
novel
and
unprecedented
p-toluenesulfonic
acid-catalyzed
dehydrative
Nazarov-type
cyclization/C2-N1
bond
cleavage
cascade
reaction
of
perfluoroalkylated
3-indolyl(2-benzothienyl)methanols
has
been
developed.
This
provides
an
efficient
practical
protocol
for
the
construction
highly
functionalized
benzothiophene-fused
cyclopentenones
with
exclusive
stereoselectivity.
In
addition,
this
transformation
also
delineates
a
rare
example
involvement
selective
C2-N1
indoles.
Organic Letters,
Journal Year:
2022,
Volume and Issue:
24(40), P. 7416 - 7420
Published: Oct. 3, 2022
Here,
we
report
the
first
total
syntheses
of
daphnezomine
L-type
alkaloids
L
methyl
ester
and
calyciphylline
K
via
late-stage
C–N
bond
activation.
The
synthesis
secodaphniphylline-type
alkaloid
caldaphnidine
D
was
also
achieved
a
similar
strategy.
Other
key
transformations
employed
in
our
were
facile
vicinal
diol
olefination
an
efficient
radical
cyclization
cascade.
Biological
studies
indicated
two
synthetic
compounds
possess
promising
neuroprotective
activity.
Synthesis,
Journal Year:
2024,
Volume and Issue:
56(08), P. 1273 - 1284
Published: Jan. 12, 2024
Abstract
Here,
we
wish
to
describe
our
detailed
efforts
in
the
total
synthesis
of
three
calyciphylline
A-type
alkaloids,
namely
(+)-daphlongamine
E,
(+)-calyciphylline
R,
and
(–)-10-deoxydaphnipaxianine
A.
Important
steps
approach
include
a
Pt-catalyzed
nitrile
hydration,
Babler–Dauben
rearrangement,
novel
selective
amide
reduction
tactic,
an
oxidative
Nazarov
cyclization
via
unfunctionalized
tertiary
divinyl
carbinol
(TDC).
