Chemistry of the Podocarpaceae. LXXII. Ring-C Modifications of Totarol

1988 ◽  
Vol 41 (8) ◽  
pp. 1171 ◽  
Author(s):  
RC Cambie ◽  
GR Clark ◽  
CEF Rickard ◽  
PS Rutledge ◽  
GR Ryan ◽  
...  
Keyword(s):  
Single Crystal ◽  
High Yield ◽  
The Novel ◽  
X Ray Diffraction ◽  
Lithium Iodide ◽  
Rearrangement Product ◽  
Ring Systems ◽  
X Ray ◽  
Naturally Occurring

Totarol (1) has been converted into conjugated dienolides which have the B/C-ring systems found in naturally occurring nagilactones A and C and their analogues. Thus, treatment of the epoxide (11) with titanium(IV) tetrachloride affords the desired 7,9(11)- diene (12) and the saturated γ- lactone (23). Treatment of the epoxide (11) with diazabicyclo [3.4.0]non-5-ene gives a high yield of the butenolide (24); the alcohol (25) has been shown to be an intermediate in this reaction. Treatment of (11) with lithium iodide dihydrate in collidine gives the butenolides (24) and (26), and the novel rearrangement product (27) which is slowly converted on standing into the epoxide (29). Treatment of (11) with anhydrous lithium iodide gives the α- pyrone (30). The structures of compounds (11), (23), (24) and (29) have been determined by single-crystal X-ray diffraction measurements.

Ten-Vertex Polyhedral Monocarbaborane Chemistry. The Novel High-Yield Formation of the Ten-Vertex closo Compound [6-(PMe2Ph)-closo-1-CB9H9] from the Thermolysis of [8,8-(PMe2Ph)2-nido-8,7-PtCB9H11]

1993 ◽  
Vol 58 (12) ◽  
pp. 2924-2935 ◽  
Author(s):  
Jane H. Jones ◽  
Bohumil Štíbr ◽  
John D. Kennedy ◽  
Mark Thornton-Pett
Keyword(s):  
Nmr Spectroscopy ◽  
Diffraction Analysis ◽  
High Yield ◽  
Monoclinic Space Group ◽  
The Novel ◽  
X Ray Diffraction ◽  
Metal Centre ◽  
X Ray ◽  
Yield Formation ◽  
Boiling Toluene

Thermolysis of [8,8-(PMe2Ph)2-nido-8,7-PtCB9H11] in boiling toluene solution results in an elimination of the platinum centre and cluster closure to give the ten-vertex closo species [6-(PMe2Ph)-closo-1-CB9H9] in 85% yield as a colourles air stable solid. The product is characterized by NMR spectroscopy and single-crystal X-ray diffraction analysis. Crystals (from hexane-dichloromethane) are monoclinic, space group P21/c, with a = 903.20(9), b = 1 481.86(11), c = 2 320.0(2) pm, β = 97.860(7)° and Z = 8, and the structure has been refined to R(Rw) = 0.045(0.051) for 3 281 observed reflections with Fo > 2.0σ(Fo). The clean high-yield elimination of a metal centre from a polyhedral metallaborane or metallaheteroborane species is very rare.

Structural Study of an Unusual Diels-Alder Adduct

1992 ◽  
Vol 45 (12) ◽  
pp. 2089 ◽  
Author(s):  
EL Ghisalberti ◽  
BW Skelton ◽  
AH White
Keyword(s):  
Single Crystal ◽  
Diffraction Study ◽  
Structural Study ◽  
Spectroscopic Studies ◽  
Diels Alder ◽  
X Ray Diffraction ◽  
X Ray ◽  
Naturally Occurring ◽  
Chemical Evidence ◽  
Alder Adduct

The structure of the compound obtained on heating the naturally occurring clerodane furanoditerpene (1) had been formulated as (2) on the basis of spectroscopic studies. A single-crystal X-ray diffraction study on the dihydro derivative of (2) has confirmed this and provides support for the stereochemistry previously assigned to (1) on the basis of chemical evidence.

Synthesis of Triferrocenylbenzenes by Tantalum(V)-Catalyzed Cyclotrimerization of Ethynylferrocene. The Crystal Structure of 1,3,5-Triferrocenylbenzene

1997 ◽  
Vol 62 (10) ◽  
pp. 1577-1584 ◽  
Author(s):  
Petr Štěpnička ◽  
Ivana Císařová ◽  
Jan Sedláček ◽  
Jiří Vohlídal ◽  
Miroslav Polášek
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Single Crystal ◽  
High Yield ◽  
Isomer Mixture ◽  
State Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr ◽  
Yield Formation

Exclusive, high-yield formation of the cyclotrimers of ethynylferrocene (1) was observed when TaCl5 in benzene was employed as catalyst. Analysis of the resulting isomer mixture by means of HPLC and 1H NMR revealed the presence of 1,3,5-triferrocenylbenzene (sym-2) and 1,2,4-triferrocenylbenzene (asym-2) in the ratio of 4 : 6. A small amount of pure sym-2 isomer was isolated, and its solid-state structure was established by single-crystal X-ray diffraction. The molecules of sym-2 possess a distorted up-up-down arrangement of the ferrocenyl groups attached to the benzene ring.

scholarly journals SYNTHESIS AND STRUCTURE OF TWO PALLADIUM(II) COMPLEXES BEARING ACETONITRILE AND N-HETEROCYCLIC CARBENE DERIVED FROM IMIDAZOLE

2019 ◽  
Vol 57 (4) ◽  
pp. 468
Author(s):  
Mai Thi Cam Truong ◽  
Chi Thi Thanh Nguyen
Keyword(s):  
Single Crystal ◽  
Diffraction Study ◽  
13C Nmr ◽  
Nmr Spectra ◽  
High Yield ◽  
13C Nmr Spectra ◽  
Trans Position ◽  
X Ray Diffraction ◽  
Imidazolium Chloride ◽  
X Ray

The reaction of [PdCl2(CH3CN)2] (1) with either 1,3-bis(2,4,6-trimethylphenyl)imidazolium chloride (IMes·HCl) or 1,3-bis(2,6-diisoproylphenyl)imidazolium chloride (IPr·HCl) in the present of Ag2O afforded two mixed monocarbene-CH3CN complexes, namely trans-[PdCl2(CH3CN)(IMes] (2) and trans-[PdCl2(CH3CN)(IPr)] (3), with the high yield (85-90%). The structure of 2 and 3 were elucidated by ESI mass, IR, 1H NMR and 13C NMR spectra. For 2, single-crystal X-ray diffraction study was also carried out. The results show that the CH3CN in 2 and 3 coordinates with Pd(II) via the N atom, the deprotonated imidazolium salts are bound up with Pd(II) via the C atom (NCHN) and occupy trans-position in comparison with the CH3CN.

Studies of Australian Soft Corals. XV. The Structure of Pachyclavulariadiol, a Novel Furano-Diterpene from Pachyclavularia violacea

1979 ◽  
Vol 32 (10) ◽  
pp. 2265 ◽  
Author(s):  
BF Bowden ◽  
JC Coll ◽  
SJ Mitchell ◽  
CL Raston ◽  
GJ Stokie ◽  
...  
Keyword(s):  
Single Crystal ◽  
Diffraction Study ◽  
Furan Ring ◽  
Soft Coral ◽  
Soft Corals ◽  
X Ray Diffraction ◽  
Isopropyl Group ◽  
X Ray ◽  
Naturally Occurring

.Pachyclavulariadiol (3) and its naturally occurring mono-(4) and di-acetylated (5) derivatives have been isolated from the soft coral Pachyclavularia violacea. Their structures were deduced spectroscopically and confirmed by a single-crystal X-ray diffraction study on the diol(3). Each compound is shown to be a highly functionalized cembranoid diterpene with the isopropyl group elaborated as a furan ring.

Lewis-Base Adducts of Group 11 Metal(I) Compounds .XLV. Conformational Systematics of [(N-base)1(AgX)1]N Complexes

1989 ◽  
Vol 42 (1) ◽  
pp. 149 ◽  
Author(s):  
LM Engelhardt ◽  
S Gotsis ◽  
PC Healy ◽  
JD Kildea ◽  
BW Skelton ◽  
...  
Keyword(s):  
Solid State ◽  
Single Crystal ◽  
Metal Atom ◽  
Lewis Base ◽  
The Novel ◽  
X Ray Diffraction ◽  
Nitrogen Base ◽  
X Ray ◽  
Structural Types ◽  
Solid State Structures

A number of 1 : 1 silver(1) halide/nitrogen base adducts, [ LAgX ], have been synthesized by recrystallization of the parent silver(I) halide from the neat base, and their solid state structures determined by single-crystal X-ray diffraction and rationalized in terms of the hierarchy of structural types described in the preceding papers based on steric profile of the base. In consequence of increased metal atom size (cf. Cu), a more limited array of structural types is observed.[(pyridine) AgBr,I ] ∞, [(2,4,6-trimethylpyridine) AgCI,Br,I ] ∞ and [( quinaldine ) AgCI,Br ] are 'stair' polymers; [( piperidine ) AgBr,I ]4 and [(2,2,6,6-tetramethyIpiperidine) AgI ]4 are 'cube' tetramers, while [( diethylamine ) AgCI,Br,I ] provide the first complete metal halide series of the novel 'tube' polymer.

scholarly journals Metal-mediated reactions towards the synthesis of a novel deaminolysed bisurea, dicarbamolyamine

2018 ◽  
Vol 16 (1) ◽  
pp. 535-543 ◽  
Author(s):  
Felix Odame ◽  
Eric Hosten ◽  
Zenixole R. Tshentu
Keyword(s):  
Single Crystal ◽  
Cobalt Acetate ◽  
Nitrate Hexahydrate ◽  
The Novel ◽  
Acetate Tetrahydrate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Benzoyl Isothiocyanate ◽  
Cerium Nitrate Hexahydrate ◽  
Cobalt Acetate Tetrahydrate

AbstractA new selective cobalt acetate tetrahydrate or cerium nitrate hexahydrate mediated cleavage of the C–N bond of a benzoyl isothiocyanate derivative to give (carbamoylamino)methanethioamide is presented. The cleavage of the C–N could not be achieved in the absence of thione. The novel silver-mediated conversion of a thione to the carbonyl was achieved on 1-((benzamido)formyl)urea and replicated on (carbamoylamino)methanethioamide to give the deaminolyzed bisurea (dicarbamolyamine). The compounds were characterized by IR, NMR, microanalysis and GC–MS. The single crystal X–ray diffraction studies of the crystal structures of compounds I, II, III and V is discussed.

scholarly journals Acid catalyzed cyclodimerization of 2,2-bis(trifluoromethyl)-4-alkoxy-oxetanes and -thietanes. Synthesis of 2,2,6,6-tetrakis(trifluoromethyl)-4,8-dialkoxy-1,5-dioxocanes and 3,3,7,7-tetrakis(trifluoromethyl)-9-oxa-2,6-dithia-bicyclo[3.3.1]nonane

2010 ◽  
Vol 6 ◽  
Author(s):  
Viacheslav A Petrov ◽  
Will Marshall
Keyword(s):  
Single Crystal ◽  
High Yield ◽  
X Ray Diffraction ◽  
X Ray ◽  
Acid Catalyzed ◽  
Yield Formation ◽  
Spontaneous Reaction

Treatment of 2,2-bis(trifluoromethyl)-4-R-oxetanes (R = C2H5O, n-C3H7O, n-C4H9O) with BF3·OEt2 in CH2Cl2 solvent results in spontaneous electrophilic [4 + 4] cyclodimerization with the formation of the corresponding 2,2,6,6-tetrakis(trifluoromethyl)-4,8-dialkoxy-1,5-dioxocanes, isolated in 31–42% yield. The structures of two products (R = C2H5O and n-C3H7O) were established by single crystal X-ray diffraction. The corresponding oxetane carrying the bulky t-C4H9O group has different reactivity towards BF3·OEt2, slowly producing a mixture of two acyclic, unsaturated products. Clean and spontaneous reaction with alcohols is another interesting transformation of oxetanes described in this paper. The reaction leads to high yield formation of the corresponding acetals (CF3)2C(OH)CH2CH(OR)OR′. Structurally related 2,2-bis(trifluoromethyl)-4-R-thietanes (R = i-C3H7O, t-C4H9O and C2H5O) have different reactivity towards electrophiles. They are totally inert to the action of BF3·OEt2 and rapidly react with a protic acid (H2SO4) forming the same product, 3,3,7,7-tetrakis(trifluoromethyl)-9-oxa-2,6-dithia-bicyclo[3.3.1]nonane in 35–50% yield. The structure of this product was established by single crystal X-ray diffraction.

High-yield, regiospecific bis-functionalization of C70 using a Diels–Alder reaction in molten anthracene

2014 ◽  
Vol 50 (73) ◽  
pp. 10584-10587 ◽  
Author(s):  
Venkata S. Pavan K. Neti ◽  
Maira R. Cerón ◽  
A. Duarte-Ruiz ◽  
Marilyn M. Olmstead ◽  
Alan L. Balch ◽  
...  
Keyword(s):  
Single Crystal ◽  
Thermal Gravimetric Analysis ◽  
Alder Reaction ◽  
Diels Alder ◽  
High Yield ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diels Alder Reaction

A regiospecific bis-adduct of C70 with anthracene was prepared with unusually high yield (68%) by the Diels–Alder reaction in the absence of solvent (melt). The structure of the bis-adduct was an unexpected 12 o'clock isomer, as determined by single crystal X-ray diffraction, thermal gravimetric analysis (TGA) and spectroscopy.

Structure of δ1-CoZn7.8, an example of a phason pinning–unpinning transformation?

2003 ◽  
Vol 59 (6) ◽  
pp. 720-729 ◽  
Author(s):  
Hanna Lind ◽  
Magnus Boström ◽  
Vaclav Petříček ◽  
Sven Lidin
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
The Novel ◽  
X Ray Diffraction ◽  
Mechanical Grinding ◽  
Filtration Method ◽  
X Ray ◽  
Novel Structure ◽  
Metastable Structure ◽  
Structural Modulation

The novel structure of the δ1 phase in the cobalt–zinc system was determined by single-crystal X-ray diffraction. The structure features fused double icosahedra linked by edge- and face-sharing. The δ1-CoZn7.8 structure is incommensurately modulated along the columnar b direction. The extent of the linear pentagonal antiprismatic intergrowth is limited to a maximum of two overlapping icosahedra because of geometric demands and radii relations. Even this limited fusion of icosahedra leads to strain that is believed to be the origin of the structural modulation. The compound was synthesized using a centrifugation-aided filtration method which yielded single crystals grown on cobalt pieces in a zinc-rich melt. The (3 + 1)-dimensional superspace group is F2/m(0β0)s0 and the modulation wavevector was determined to q = 0.234b*. The partial amorphization of the sample when subjected to mechanical grinding is an indication of a metastable structure. The incommensurability of the structure may be seen as an ordered pinning of phasons.

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