вход по аккаунту


Novel Cobalt- and Nickel-Clusters with S and PPh3 as Ligands; Crystal Structures of [Co7S6(PPh3)5Cl2] [Co6S8(PPh3)6]+[CoCl3(THF)] [Ni8S6Cl2(PPh3)6] and [Ni8S5(PPh3)7].

код для вставкиСкачать
For clarification of the stereochemistry in the eightmembered ring, the methine proton on C6 and one of the
methyiene protons on C8 were irradiated separately in a
second hetero-NOE experiment. On the basis of the 'Hcoupling constants for their coupling with the neighboring
methylene protons it could be assumed that they were the
protons which lie relatively close to the lactone bridge in
the case of l a but not so in the case of l b (Fig. 3).
Hence, in the presence of l a an NOE effect on C11 had
to be expected from at least one of these protons. Indeed,
the difference spectrum (Fig. 4c) shows, in the case of the
irradiation of the proton on C6, a signal of C 11 as well as
the expected signals of C7 and C I ' (ester carbonyl-C). In
the second difference spectrum (Fig. 4b), after irradiation
of the one proton of the methylene group C8, only the expected signal of C7 appears. This confirms the finding of
the preliminary NOE experiment and, due to the spatial
proximity of the proton of the methine group C6 to C11
(lactone carbonyl-C), proves the presence of structure l a .
Thus, as a result of increased selectivity, the hetero-NOE
experiment can be successfully employed even when
strongly overlapping proton spectra are obtained.
1' 0 0 ~ 1 - 1 ~
Fig. 2. J3-Keto esters I and 2
Fig. 3. Stereoisomers of 1. The bonds to the H-atoms on C2a, CS, C6, C8,
and C9 are shown.
February 22, 1985;
revised: May 17, 1985 [ Z 1183 IE]
German version: Angew. Chem. 97 (1985) 701
nary measurement of the hetero NOE effect, the multiplet
lines of the C5 protons and then of the C9 protons were, as
described above, successively irradiated several times : the
two spectra were (in each case at the stage of the free induction decay) subtracted from each other. The I3C-NMR
difference spectrum (Fig. 4a) shows a positive signal for
C4a and, thus, close proximity to the protons on C5, and a
negative signal for C9a, and thus, a close proximity to the
protons on C9. Since the quaternary C-atoms C4a and C9a
can be identified from their chemical shifts, the position of
the lactone bridge relative to the methine group C6 is established and, thus, also the structure of the main component 1.
[ I ] J. K. M. Sanders, Prog. Nucl. Magn. Reson. Specfrosc. 15 (1983) 353.
121 D. Neuhaus. R. N. Sheppard, 1. R. C. Bick, J . A m . Chem. SOC.105 (1983)
[3] D. Neuhaus, J . Magn. Reson. 53 (1983) 109.
[4] M. Kinns, J. K. M. Sanders, J . Magn. Reson. 56 (1984) 518.
151 H. Kessler, C. Griesinger, J. Lautz. Anyew. Chem. 96 (1984) 434: Angew.
Chem. I n t . Ed. Engl. 23 (1984) 444; H. Kessler, C. Griesinger, J. Zarbock,
H. R. Loosli, J . Magn. Reson. 57 (1984) 33 I .
161 R. Kesse, A. Pfenninger, A. Roesle, Helr;. Chim. Actu 62 (1979) 326.
Novel Cobalt- and Nickel-Clusters with S and PPh3
as Ligands; Crystal Structures of [ C O ~ S ~ ( P P ~ ~ ) ~ C I ~ I
I C O ~ S B ( P P+lCoCI3(THF)l-,
and INi8SS(PPh3),1**
By Dieter Fenske, * Johannes Hachgenei, and
Johannes Ohmer
We recently described a simple method for the preparation of PPh-bridged clusters of C o and Ni. Reaction of
MC12 ( M = C o , Ni) with PhP(SiMe,)2 in the presence of
Ph3P leads to the formation of SiMe,CI and [Co&,PPh)4(PPh3)4]or 1.['.211 contains four coordinatively unsaturated Ni atoms which are shielded in a crown-like fashion by Ph groups of the PPh- and PPhJigands. As a result
the cluster contains a channel of about 400-500 pm in diameter, and only small molecules, e.g. CO, can bind to the
four Ni atoms with coordination vacancies.
In attempts to prepare clusters with greater coordination
gaps we allowed S(SiMe,),'" to react with [MCL( PPh&
( l a , M = C o ; l b , M=Ni). Reactions of transition metal
halides with S(SiMe& have already been reported. Normally, metal sulfides are formed; only in one case could
[*] Prof. Dr. D. Fenske, DipLChem. J. Hachgenei, Dip1.-Chem. J. Ohmer
Fig. 4. Hetero-NOE difference spectra (6 values). a) Difference of the "CNMR spectra in the region of C4a and C9a after irradiation of the protons
on CS and C9; b), c) difference of the "C-NMR spectra in the carbonyl region after irradiation of the proton o n C8 (b) and of the proton on C6 (c).
0 VCH VerlagsyesellschaJi mhH. 0-6940 Wernherm, I985
lnstitut fur Anorganische Chemie der UniversitXt
Engesserstrasse, Geb. Nr. 30.45, D-7500 Karlsruhe (FRG)
This work was supported by the Deutsche Forschungsgemeinschaft and
the Fonds der Chemischen Industrie. We thank co-workers at the Institut fur Kristallographie der Universitat Karlsruhe for help with the crystallographic measurements.
0570-08313/85/0808-0706 $ 02.50/0
Angew. Chem. I n r . Ed. Engl. 24 (1985) No. 8
the formation of a binuclear complex be observed.14' Reaction of l a with S(SiMe,)2, on the other hand, leads to formation of clusters. With tetrahydrofuran as solvent, a crystalline black precipitate consisting of 2 and 3, separates
out within a few minutes."'
Reaction of the complex 2 with [NBu4]PFh furnishes
2 and [Co,S,(PPh,),]PF,
are paramagnetic, and, at
300 K, have magnetic moments of 4.55 and 2.49 p8, respectively. This manifests itself, e.g., in the 'H-NMR spectrum
of 2 by various isotropic shifts for the phenyl protons
(6= 6.60-7.50).
The structures of 2 and 3 were determined by X-ray
crystallography.[" 2 contains isolated [Co,(p,-S),(PPh,),]
(Fig. I ) and [CoCI,(THF)]- ions.[71The cluster cation consists of an almost regular Co,-octahedron (i symmetry),
whose Co?-faces are each bridged by a p3-S ligand.18 91 In
addition, each C o atom is bound to the P-atom of a PPh,
ligand. The Co6-cluster contains 97 valence electrons, i.e.
13 electrons more than expected according to the 18-electron rule.'"' ' ' I The Co-Co bond lengths (280-282 pm) correspond to those found in [CO,S,(PE~,),]+,"~~
but are distinctly longer than those in [co,(c0)]5]'and
[ C O , ( C O ) ~ ~ (246-254
]~~ m ) . 14)~ ' ~
pm. Three of the Co, faces (CoI, c o 3 , C06; C o l , c o 4 ,
c o 5 ; c o 4 , C06, c o 7 ) are bound to p3-S ligands (Co-S
213.6-222.8 pm). The Co atoms in 3 are coordinated to a
distorted tetrahedral array of three S atoms and the P atom
of the PPh3 ligand (Col, C02, c o 4 , C06, c o 7 ) or three S
atoms and a CI ligand (co3, co5). The Co-Co distances
in the cluster are 257.4-263.7 pm. These values are comparable with the Co-Co bond lengths in [Co,S,(SPh),j4(263-266 pm).["I Three bonds (Col -co4, C o I -C06,
C04-C06), however, are markedly longer (286.1-289.7
pm). Presumably, this is the reason for 3 (99 valence electrons) already reacting with C O at room temperature to
give [Co7(CO),Cl,S,(PPh3),1 (v(CO)= 1960, 1940 cm I,
105 valence electrons).
Fig. I. Structure of the [(CO,,(~,-S)~(PP~,),]'
ion in the crystal of 2 (without
phenyl groups) [6]. PI-P3 are the atoms of the PPh, ligands. (The dashed
atomic positions are generated by the inversion center.) Important bond
lengths [pml ( L 0 . 2 pm) and bond angles ["I (L0.1"):Co-Co 279.8-282.8,
Co-(p,-S) 220-223, Co-P 217.8-218.1 ; Co-Co-Co 59.4-60.5, 89.3-90.7,
P-Co-(p~-s) 91-1 1 I , SI-Col-S2 86.9, S2-Col-S3' 88.1, S3'-Col-S4
87.7, S4-col-SI 87.8. SI-COI-S~'156.8, S2-Col-S4 156.5.
A complex containing seven C o atoms is present in 3
(Fig. 2). Formally, the Co,-cluster can be derived from a
cube from which one corner has been removed. The cluster
distorts, and forms a polyhedron of three Co4-faces and
four Co,-faces. The polyhedron faces (Col, C02, c 0 3 ,
c o 5 ; c 0 2 , c o 3 , C06, c o 7 ; c 0 2 , c o 4 , c o 5 , c o 7 ) are not
planar; the Co atoms lie 16 pm above or below the medium plane. The p4-S-Co ligand distances are 217-225
Angen. Chem Irit. Ed. Engl. 24 / 1 9 R S ) No. 8
Fig. 2. Crystal structure of the cluster 3 (without phenyl groups) [6] PI. P2,
P4, P6 and P7 are the P atoms of the PPhl ligands. Important bond lengths
[pm] and bond angles ["I ( k O . l ' ) : Col-Co3 259.3(2), Col-Co4 286.1(2),
COl-CO5 260.2(2). C O I-CO6 289.6(2), C02-C03 263.7(2), CO2-Co5
265.2(2). C02-CO7 260.4(2), C03-Co6
258.7(2), Co4-COS 257.4(2),
C04-Co6 289.7(2), CO4-Co7 260.5(2). C06-Co7 257.7(2), Co-P 220.9227.5(4), CO-CI 220.8-222.8(4), COILS 214.0-218.1(3), Co2-S 217.0220.0(4), Co3-S 221.0-225.2(3), c o 4 - s 215.8-223.3(3), cO5-s 222.5224.8(3), Co6-S 214.0-217.1(3), Co7-S 217.6-220.8(3): Co-Con-Co:
C o n = C o l 55.9-101.7, C 0 2 95.2-95.8, Co3 68.0-81.8. Co4 55.6-102.1, Co5
67.1-81.9, C06 56.1-100.9, C07 68.0-82.6: CO-(pj-S)-Co 71.8-85.3, Co-(p4S)-Co 70.1-121.9, P-Co-S 94-1 19.4, CI-Co-S 109.8-116.3.
The reaction of PR3 complexes of the transition metal
halides with S(SiMe,)* also leads in other cases to Sbridged clusters. For example, reaction of [NiC12(PPh3),]
with S(SiMe3)2 furnishes a mixture of 4 and a substance
whose structure is so far unknwon.['"] According to analysis it is the complex 5 , which is readily soluble in T H F and
acetone and can be separated from the sparingly soluble
A crystal structure analysis of 4 (Fig. 3) showed that a
slightly distorted Nig cube (1 symmetry) is present which
bears a p4-S ligand on each face.["] In addition, the Ni
atoms are bound to the P atom of the PPh3 ligand ( N i l ,
Ni2, Ni4, Nil', Ni2', Ni4') or to CI- (Ni3, Ni3'). Consequently, the Ni is coordinated in a distorted tetrahedral
fashion. 4 contains 118 valence electrons, and the Ni-Ni
distances (266-270 pm) compare with those found in other
Nig clusters.",*. IX1
0 V C H Verla.qsgesel/schafi mhH, 0-6940 Weinheirn, 1985
$ 02.50/0
attached to Nil, Ni2, Ni3, Ni4, Ni5, Ni6, and Ni8, not all
polyhedral faces can be occupied by S-ligands. Nil, Ni4.
and Ni6 and Ni3, Ni5, and Ni8 are bound to u3-S ligands.
The Ni-S bond lengths (21 1-217 pm) and Ni-S-Ni bond
angles (76.7-81.5') are comparable with those in other
complexes that contain p3-S ligands.[2'11S3, S4, and S5 can
also be regarded as p3-ligands (Ni-S 213-219 pm). However, the Ni-S-Ni bond angles (72.4-137.4") are considerably larger. In addition there is still weak interaction between Ni7 and S3 (258.6 pm) and between Ni7 and S4
(268.8 pm).
The Ni-Ni distances can be classified into three groups:
1) 240-252 pm, from Ni7 to the Ni atoms bound thereto; 2)
263-268 pm; 3) 275-297 pm (Ni2-Ni6, Ni4-Ni6,
Ni2-Ni5, Ni2-Ni3, Ni5-Ni8, Ni4- Ni6). Comparable
bond lengths have also been observed in other Ni clusters.120.2 11
Received: April I I, 1985:
revised: May 14, 1985 [Z 1263 IE]
German version: Angew. Chem. 97 (1985) 684
Fig. 3. Crystal structure of the cluster 4 (without phenyl groups). PI, P2, and
P4 correspond to the P atoms of the PPh3 ligands (171. Important bond
lengths [pm] ( f O . l pm) and bond angles ["I (fO.1"): Ni-Ni 265.8-271.0,
217.9-223.8, Ni-P 224.5-226.3, Ni-CI 220.3; Ni-Ni-Ni 88.292.6, P-Ni-(p4-S) 107.9-125.8, CI-Ni-(pL,-S) 109.8-121.7, Ni-(pa-S)-Ni
74.2-76.9 (CIS), 116.0-119.6 (trans).
Reduction of 4 with sodium amalgam in THF in the
presence of C O affords [Ni,(CO)2S,(PPh,)6]. Intercalation
of metal atoms, as occurs during the reduction of
was, however, not observed.[*'
Reaction of 5 with Zn (in THF) leads to formation of 6
in 60%
6["l (Fig. 4) is a Nix cluster ( 1 14 valence electrons) consisting of two edge-to-edge coupled trigonal bipyramids.
Owing to the large spatial requirement of the PPh3 ligand
Fig. 4. Crystal structure of the cluster 6 (without phenyl groups). PI-P6 and
PS correspond t o the P atoms of the PPh, ligands [19J. Important bond
lengths [pmJ ( f 0 . 3 pm) and bond angles ["I (?O.lo): Nil-Ni2 268.0,
NilLNi4 268.8, Nil-Ni6 263.0, Ni2-Ni3 276.7, Ni2-Ni5 276.6, Ni2-Ni6
295.7, Ni2-Ni7 239.5, Ni3-Ni5 267.2, Ni3-Ni7 247.2, Ni3-Ni8 267.2,
Ni4-Ni6 275.5, Ni4-Ni7 250.9, Ni5-Ni7 241.6, Ni5-Ni8 282.2, Ni6-Ni7
243.9, Ni7-Ni8 252.7, Ni-P 214.8-218.5, Ni-(p,-S) 210.4-221.0, S3-Ni7
258.6, S4-Ni7 268.8; Ni-Nin-Ni: N i n = N i l 55.2-110.5, Ni2 53.0-113.0,
Ni3 54.1-108.6, Ni4 55.0-57.8, Ni5 54.6-61.1, Ni6 51.6-101.1, Ni7 64.6-144.7,
Nix 53.4-58.1; Ni-SI-Ni 76.2-80.1, Ni-SZ-Ni 76.2-81.5, Ni-S3-Ni 78.9118.4, NibS4-Ni 75.8-1 19.5, Ni-S5-Ni 72.4-137.4.
0 VCH Verlagsgesellschaft m b H , 0-6940 Weinheim. 1985
CAS Registry numbers:
2, 97415-85-5; 3, 97403-25-3; 4, 97415-86-6: 5, 97403-27-5; 6 , 97403-28-6:
[CoC12(PPhl):], 14126-40-0; [CoS,(PPh,),]PF,, 97403-30-0: [NiCI2(PPh,)J,
14264-16-5; [Ni,(CO)&(PPh&], 97403-3 1-1.
[I1 D. Fenske, R. Basoglu, J. Hachgenei, F. Rogel, Angew Chem. 96 (1984)
160; Angew. Chem. In!. Ed. Engl. 2.3 (1984) 160.
[2] D. Fenske, J . Hachgenei, F. Rogel, Angew. Chem. 96 (1984) 9 5 9 ; Angew.
Chem. Inr. Ed. Engl. 23 (1984) 982.
[3] M. Schmidt, H. Ruf, Z . Anorg. Allg. Chem. 321 (1963) 276.
[4] Y. Do, E. D. Simhon, R. H. Holm, Innrg. Chem. 22 (1983) 3809; E. W.
Abel. C. R. Jenkins, J . Organornet. Chem. 14 (1968) 285: J . F. Dorfmann,
J.-J. Girerd, E. D. Simhon, T. 1). P. Stack, R. H. Holm, Inorg. Chem. 23
(1984) 4407.
[5] Procedure: A solution of la (16 g. 0.0245 mol) in T H F (100 mL) was
prepared under nitrogen and treated dropwise with 4.5 g (0.0252 mol) of
S(SiMe3)2.The solution immediately changed color from blue to brown,
and a mixture of 2 and 3 precipitated (yield 6.6-7.0 gj. After addition of
100 mL of toluene and filtration, the residue was treated with toluene/
C2H4C12.About 4.1 g of 3 went into solution. (On covering the solution
with pentane, 3 was obtained as long, black crystals. Crystals of the very
sparingly soluble compound 2 were obtained by dissolution of the resid u e of crystallization in THF/C,H,CIZ. After covering the solution with
pentane, 2 separated out in the form of black crystals.
[6] 2 crystallizes with four molecules of T H F per formula unit. Space group
Pi, Lattice constants (180 K j : a = 1482.9(5), h= 1603.6(5), c=2631.2(8)
p m ; a=88.42(3),/{=84.23(2). y=76.31(3)", Z=Z,p(Mo,,.)= 11.5 c m - ' .
Syntex R3, 2HS49', 19960 reflections, 13200 with 1 > 2 u ( I ) . Patterson
methods, Co, P, S, CI anisotropic, Ph refined as rigid group (C-C 139.5
pm). R , = 0.078, R? = O.O6Y.-3:
crystals from t o l u e n e / C ~ h ~ C l / p e n t a n e .
3 crystallizes with I mole of toluene per formula unit. Space group
P2,2,2,. Lattice constants (180 K): a = 1813.7(7), h= 1883.5(7),
c=2896.2(10) p m ; Z = 4 , ,u(MoKn)=13.5 c m - ' . Syntex R3, 2H150",
10716 reflections, 8629 reflections with />2rr(l). Patterson methods.
Co, P, S , CI, anisotropic, C atoms of the Ph groups isotropic (H calculated). R , =0.063, Rz=0.059. Further details of the crystal structure investigations are available on request from the Fachinformationszentrum
Energie Physik Mathematik, D-75 14 Eggenstein-Leopoldshafen 2. on
quoting the depository number CSD 51 402, the names of the authors.
and the full citation of the journal.
[7] Important bond lengths [pml: Co-CI 222-223(0.2), Co-01 206.2( lo),
01-LCI 144(2), 01-LC4 145(2). LCI-LC2 155(2), LC2-LC3 151(3),
LC3-LC4 151(3), (LCm and 01: C atoms and 0 atom of the T H F ligand). Bond angles ["I (k0.2"): CII-Co7-CI2
115.0, Cll-Co7-CI3
101.0, CIZ-Co7-CI3
118.1, C12-Co7-01
114.2, CII-Co7-01
C13-Co7-0 I 100.3.
[S] H. Vahrenkamp, Angew. Chem. 87 (1975) 363; Angew. Chem. I n t . Ed.
Engl. 14 (1975) 322, and references cited therein; G. Henkel, W. Tremel.
8. Krebs, ibrd. 95 (1983) 314 and 22 (1983) 318; Angew. Chem. Suppl.
1983. 307.
[Y] L. L. Nelson, F. Yip-Kwailo, A. D. Rae, L. F. Dahl, J . Organomef.
Chem. 225 (1982) 309.
(lo] F. A. Cotton, E.,Haas, Inorg. Chem. 3 (1964) 10.
111) J . W. Lauher, J . A m . Chem. Soc. 100 (1978) 5305
Angew. Chem. Int. Ed. Engl. 24 119851 N o . 8
112) F. Cecconi, C. A. Ghilardi, S. Midollini, J. Chem. SOC.Chem. Commun.
l Y & / . 640: Inorg. Chim. Acta 64 (1981) L47; ibid. 76 (1983) L183.
1131 P. Chini, V. Albano, C. Scatturin, J. Organomet. Chem. I 5 (1968) 423.
[I41 V. G. Albano. P. L. Bellon, P. Chini, V. Scatturin, J. Organomer. Chem.
16 (1969) 461.
[I51 G. Christou, K . S. Hagen, R. H. Holm, J. Am. Chem. SOC. 104 (1982)
[I61 Procedure: l b (16.3 g, 0.025 mol) was dissolved in T H F (100 mL) under
N Land treated with 13.4 g (0.075 mol) of S(SiMe3)>.The solution rapidly
turned brown, and a fine crystalline precipitate separated out. After addition of 100 mL of toluene and filtration, 6.2 g of the reaction mixture
were obtained, 1.6 g of which went into solution on treatment with T H F
(100 mL). The residue consisted of pure 4 (66% yield based on
[NiCI,(PPh,)J). The T H F solution was treated with 2 g of zinc powder
and heated to about 60°C for 2 h. After filtration the solution was covered with heptane. 6 crystallized out at the phase boundary as black,
flaky crystals. Crystals of 4 were obtained on recrystallization from toluene ;C2H4C12.
1171 4 crystallizes with I mole of CZH4C12per formula unit. Space group:
P2,/n. lattice constants (180 K): a = 1683.5(5), b = 1553.8(3), c=2116.4(8)
pm;/3=95.21", Z=4,p(MoKn)=16.7 c m - ' . Syntex R3,2BS55", 13716
reflections, 10889 with I > 2o(T), empirical absorption correction. Patterson methods, all atoms (except H) refined anisotropically, R , =0.053,
R2= 0.054 (61.
[I81 L. D. Lower, L. F. Dahl, J . Am. Chem. SOC.97 (1975) 6917.
[I91 Crystals of 6 from THF/pentane. 6 crystallizes with 2 moles of T H F
(disordered) and 1 mole of pentane. Space group: P2,/n, lattice constants (180 K): a=1656.8(4), b=1664.3(4),
C=4917.2(11) pm;
p=94.40(2)", p(MoK,)=13.3 cm-', Z = 4 . Syntex R3, 2 8 1 4 5 " , 19189
reflections. 13528 with I > 2u(J), empirical absorption correction. Patterson methods, Ni, P, S anisotropic, Ph refined as rigid group (C-C
139.5 pm). R , =0.078, R2=0.079 [6].
[20] C. A. Ghilardi, S. Midollini, L. Sacconi, Inorg. Chim. Acta 31 (1978)
L431; H. Vahrenkamp, V. A. Uchtmann, L. F. Dahl, J. Am. Chem. Sac.
YO (1968) 3272.
[21] F. Cecconi, C . A. Ghilardi, S. Midollini, Inorg. Chem. 22 (1983) 3802.
Crinipellins, the First Natural Products with a
Tetraquinane Skeleton**
By Timm Anke, Jutta Heim, Falk Knoch, Ursula Mocek,
Bert Stefian, and Wolfgang Steglich*
Dedicated to Professor Hans Muss0 on the occasion of
his 60th birthday
Several years ago, we described an antibiotic that is produced by cultures of the basidiomycete Crinipellis stipitaria
(Agaricales)."' An investigation of several strains of this
fungus has now led to the isolation of several related compounds, crinipellin A, crinipellin B, and O-acetylcrinipellin A, the latter of which is identical with the "crinipellin"
we described earlier. In addition to these antibiotically active compounds, two inactive accompanying substances
were found, dihydrocrinipellin B and tetrahydrocrinipellin A.
According to its N M R spectra (Table ]),I2] crinipellin A
possesses a cyclopentane ring that contains an a-methylene ketone group and an epoxide function in an analogous arrangement to the hirsutane derivatives complicatic
acid['] and hypnophilin 4.l4]This is shown by, among other
things, the characteristic long-range coupling 5J= 1.1 Hz
Prof. Dr. W. Steglich, Dr. B. Steffan, Dipl.-Chem. U. Mocek
lnstitut fur Organische Chemie und Biochemie der Universitat
Gerhard-Domagk-Strasse 1, D-5300 Bonn 1 (FRG)
Dr. F. Knoch
lnstitut fur Anorganische Chemie der Universitat
Gerhard-Domagk-Strasse I, D-5300 Bonn I (FRG)
Prof. Dr. 7.Anke, Dr. J. Heim
Abteilung Biotechnologie der Universitat
Paul-Ehrlich-Strasse 22, D-6570 Kaiserslautern (FRG)
Antibiotics from Basidiomycetes, Part 21. This work was supported by
the Deutsche Forschungsgemeinschaft and the Bundesministerium fur
Forschung und Technologie. We thank Prof. R. Appe/ for help in the
crystal structure determination.-Part 20: G. Schramm, B. Schwalge,
B. Steffan, W. Steglich, Liebigs Ann. Chem. 1984, 1616.
Angew Chem. Inr Ed Engl. 24 11985) No. 8
Table 1. ' H - and "C-NMR data for crinipellin A l a (400 and 100.62 MHz,
respectively, 6 values, solvent CDCI, as internal standard). The NOE relationships are indicated. All 'H- and "C-NMk assignments were confirmed
by 2D NMR data.
1-H, 1.41 (dd)
C-l 37.8 Tm
I-Hb 2.53 (dd)
3.10 (ddddd) 13.2/7.5/1.4/0.8/0,5 C-2 42.0 Dm
C-3 145.6 m
C-4 196.0 m
5-H 3.48 (dd)
C-5 58.5 Dd
C-6 77.8 m
C-7 50.0 ddd
C-8 214.5 d s
- -9-H
C-9 84.7 Ddq
4.42 (d)
C-10 53.9 m
C-ll 62.3 m
C-12 32.1 Tdd
12-H, 1.89 (ddd)
8.7/8 715.4
12-Hh 1.61 (m)
C-13 23.2 Tm
13-H,% 1.61 (m)
13-Hh 1.61 (m)
C-14 51.8 Dm
14-H 1.33 (doub.)
C-15 28.2 Dm
IS-H 2.11 (dsep) 7.0/2.5
C-16 19.6 Qm
16-CH30.85 (d)
C-17 24.8 Qm
17-CH30.82 (d)
l8-H., 5.49 (ddd)
C-18 123.5 Td
18-Hb 6.15 (dd)
C-19 15.1 Q
-19-CH3 1.04 (s)
C-20 16.2 Qdd
between the 5-H and the 18-H, trans to the carbonyl
g r o ~ p . ' ~ , 'In
' contrast, 18-Hb exhibits a 4J coupling of 1.4
Hz to the angular 2-H, which, along with the methylene
protons on C-l, forms an ABX system. The partial structure A is thus obtained. From the 'H,'H-correlated 2 D
N M R spectrum, the proton sequence B can be derived
starting from the isopropyl group, and, by selective decoupling, the acyloin moiety C can be recognized in the "CN M R spectrum. Since the signal of the 20-methyl group in
the I3C-NMR spectrum exhibits two ' J couplings to 9-H
and 14-H, the partial structures B and C can be joined. By
selective decoupling of the 19-methyl group, the multiplet
of C-6 simplifies, allowing a relationship between the partial structures A and C to be obtained. Taking into consideration the presence of four carbon rings in crinipellin and
the remaining quaternary C atom (6=62.3) gives the structure l a for crinipellin A. The relative stereochemistry can
b e determined by NOE difference measurements. Acetylation of l a with acetic anhydride/4-(dimethylamino)pyridine affords 0-acetylcrinipellin A l b , which was shown to
be identical with the natural product described earlier."'
Similarly, the constitution 2a can be derived for crinipellin B,['l and was confirmed by an X-ray structure determination16' (Fig. 1).
The structures 2b and 3b are obtained for dihydrocrinipellin BCz1and tetrahydrocrinipellin A,['] respectively. The
absence of the a-methylene ketone moiety explains the
loss of biological activity."]
0 VCH Verlagsgesellscha/i mbH. D-6940 Weinhelm, 1985
0570-0833/&5/0808-0709$ 02 50/0
Без категории
Размер файла
433 Кб
crystals, nickell, co7s6, ni8s6cl2, 5cl2, co6s8, cocl, cobalt, ligand, ni8s5, structure, thf, clusters, pph3, novem
Пожаловаться на содержимое документа