C16H2SN (MS and l3 C NMR) and showed IR absorption at 2140 cm -l (i&C). Its planar structure was .... Rappoport ed., John Wiley & Sons Ltd,. 1983, p. 836. 5. M.L. Maheswari, T.G. Jain, R.B. Bates and S.C. Bhattacharrya,. Tetrahedron, 19 ...
Tetrahedron Letters,Vol.28,No.l3,pp Printed in Great Britain
STYLOTELLINE, Stylotella
A NEW SESQUITERPENE APPLICATION
sp.
Mary
*
PaPs,
de Chimie
oo40-4039/87 $3.00 + .OO Pergamon Journals Ltd.
ISOCYANIDE
OF ZD-NMR
FROM THE SPONGE
IN STRUCTURE
DETERMINATION
Catherine
Fontaine, Dominique Laurent+ La Barre tt and Eric Guittet
Stsphane
Institut
1409-1412,1987
des Substances
Naturelles,
CNRS,
91190 Gif-sur-Yvette,
France.
’ Centre ORSTOM, BP A5, Noumsa, New Caledonia. tt Laboratoire des Plantes Msdicinales, CNRS,
RP 463, Noumga,
New
Caledonia.
Abstract: The __ sesquiterpene isocyanide stylotelline isolated from the marine . __ sponge Stylotella sp. was assigned the structure la (absolute stereochemistry) on the basis of spectral - essentially 2D-NME-- and chemical data.
Terpenoid still
isocyanides
represent
toxic,
a relatively
antibiotic
or
and
structure
la,
from the sponge
Silica
(yield 0.16%
of
Stylotella
was
gel
Stylotelline C16H2SN
(MS and
planar
structure
la,
a new 2
[aID-47' and
of
2
assigned
isocyanide,
but
cyto-
the
isolation
stylotelline
crude
extracted
with
methylene
extract
gave
-la as an oil
8
/‘I1
‘2
k.
13
la
R=
iEc
l,b
R=
NHCHO tram ___-
on
at
the
2140 basis
cm -l of
formula (i&C). NMR
/PY /
c5, =
the
IR absorption
0
,
showing here
(CHC13, c = 1.7) had the molecular showed
readily
10
15 :I
report
sesquiterpene
14
=
products
We
sponges,
dry weight).
l3 C NMR)
1
1
and continuously
chromatography
was
of natural
properties.
in marine
sp.
freeze-dried
of the sponge
found previously
rare class
antifeedant
determination
The sponge chloride.
have been
2
1409
Its data.
1410
13
In the lation
C spectrum,
sequence3
1.0~ field
(4C,
part
the
1).
In
in
bound
to nitrogen field
lowed
part
of
H-6 range
4CH3). was
broad as
further
with
Attribution
decoupled
triplets
spectrum,
was established
coupled
deduced
from
the
the
(C-5,
14N
by a J moducarbons
C-6, C-7, 13 C-5 and
spectrum
to
heteronuclear of l3 C and
2) appeared
of
straightforward
band
of the pairs
in Fig.
coupling
5CH2,
the
the
were
(not shown
of the carbons
spectrum
appeared
identification
connectivities
3CH,
of
shown
high
Fig.
multiplicity
(J z 4 H2).4
6-6 correlation
in
the
NC
as
13C-16 In the
(lH-13C)
al-
directly bonded nuclei. Proton 11 H- H COSY spectrum (Fig. 2).
as a multiplet
at
6 5.44
showing
a long
H-8.
24.1
Fig.1 - 13C
The planar at C-10
and
l3 C NMR)
The
same diene
the
crude
The The value tion
Evidence
the
was The
rence nates
with
those
was
also
or
identified of
12
of
authentic
have the
in the presence
Proton the
junction
spectrum'
observation (CHC13,
a NOE
c = 0.5}
identified formamide
of
in -lb
also'coupled - C-10
between
H NMR
of
deduced
were
of
-la during the 8s? group
came,
on
H-3ax
prepared
and
and,
NMR
data.
orienta-
(3JN H_4 = 3 Hz).~ one' hand,
the
a coupling
NH
from
an axial
to nitrogen
orientation
spectrum
fractions
from
elimination
(Fig. 2) showing diaxial
(Cal,, IR, 1H 5,6 eudesmols.
of acid.
assignments
readily 1
since
from
secondarly
3J3 4 = 12 Hz required
C-5
of -la trans
their
prepared
c1
diene
chromatographic
formed
sponge
constant
4 appeared
trans
been
the known
its properties
sample
of traces
stereochemical
of the coupling
by comparing
in the least polar
could
extraction
remaining
COSY
an
found
but
establishing
[a] +122' H-3ax
2 was
slowly
for
long-range CH3-14 from
2.
for H-4.
of
rt) giving
(MeOH, HCl l%, 30 min,
extract,
conservation proceeded
data
of -la was confirmed and the absolute configuration facile elimination of the tertiary isocyanide group
by
bond
(+)-6-selinene
NMR
structure
established
to the double
I 21.5
158.8
16:4
between on
the
from
H-3ax
other
a
and
hand,
in compound
-lb {F 124'-', ether, 16h, rt).
from -la (AcOH, by decoupling from H-4
.
-lb was not found in the sponge extract, although cooccuof isocyanides with the corresponding formamides and also isothiocya1 has often been observed in other sponges.
MULTIPLE
Fig.
2.
Contour
plot
COSY
of the 400 MHZ homonuclear
(20 mg, CD3COCD3) and a multiple
QUANTA
between
quanta
spin correlations
0 and 2.5 ppm corresponding filtered COSY experiments. 8
maps of la to a long range
1412
Acknowledgements:
We wish to thank Prof. C. Levi for his kind identification
of the sponge.
References and Notes 1. Review Articles:
D.J. Faulkner, Tetrahedron, 33, 1434 (1977);
Nat.Prod.Rep., I, 560 (1984);
ibid., 1,
w,
14 (1986).
2. The sponge was collected in the south-east of New-Caledonia at a depth of 250 m in the frame of the CNRS-ORSTOM Programme "Substances Marines d'Int&&t_ Biologique".
The Stylotella
genus is close to Hymeniacidon previously. 1
from which isocyanides have been isolated
3. C. Le Cocq and J.-Y. Lallemand, J.Chem.Soc.,Chem.Commun.,
150 (1981).
4. H.M. Walborsky and M.P. Periasamy, "The Chemistry of Functional Group", Supplement C, S. Patai and 2. Rappoport ed., John Wiley & Sons Ltd, 1983, p. 836. 5. M.L. Maheswari, T.G. Jain, R.B. Bates and S.C. Bhattacharrya, Tetrahedron, 19, 1079 (1963). 6. We thank Prof. D.H.R. Barton for a sample of eudesmols from natural 9 source. The 'H NMR spectrum of 2 has been previously reported. 13C NMR (benzene-d6): 142.69 (C), 133.81 (Cl, 125.53 (C), 118.13 (CH), 38.66 (CH2, 38.22 (CH2), 35.91 (CH), 33.56 (CH2), 32.57
(C),
23.69
KHZ) I 23.40 (CH3), 22.05 (CH3), 21.62 (CH3), 19.20 (CH2, 18.68 (CH3). 7. A. Bax and R. Freeman, J.Magn.Reson., 44, 542 (1981);
J.C. Steffens, J.L.
Roark, D.G. Lynn and J.L. Riopel, J.Am.Chem.Soc., 105, 1669 (1983). 8. The 2-D correlation maps consisted of 512 x lk data points spectra, each composed of 32 transients. A 1s delay was allowed between each scan. The additional delays used in the long range COSY experiment were set at 0.5 s. 9. G. Mehta and B.P. Singh, Tetrahedron Lett. 3961 (1975); A.F. Thomas, M. Ozainne, R. Decorzant, F. Nlf and G. Lukacs, Tetrahedron, 32, 2261 (1976); M. Suzuki, M. Segouva, H. Kikuchi, T. Suzuki and E. Kurosawa, Phytochemistry, 2,
2011 (1985).
(Received in France 6 January 1987)
