Chemical studies of the Proteaceae. IV. The structures of the major phenols of Grevillea striata; a group of novel cyclophanes

1970 ◽  
Vol 23 (1) ◽  
pp. 147 ◽  
Author(s):  
DD Ridley ◽  
E Ritchie ◽  
WC Taylor

Attempts to separate the major constituents of the phenolic fraction of the ether extract of the wood of Grevillea striata R.Br. were unsuccessful, but by chemical degradation and spectroscopic methods the structures of four of the components were deduced. They were mono- and di-methyl ethers of 17,19,22,24- tetrahydroxy(l4-p-0-o)cyclophane with a double bond at either of two positions in the aliphatic chain. The new ring system was given the trivial name "turriane". Evidence that a fifth and a sixth component were derivatives with a saturated chain, and a seventh was a derivative of a double homologue of turriane, was obtained. Synthetic experiments connected with the structure determination, and on the synthesis of tetrahydroxyturriane are described. Possible biogenetic routes to striatol and the cyclophanes are discussed.

1965 ◽  
Vol 18 (12) ◽  
pp. 2015 ◽  
Author(s):  
E Ritchie ◽  
WC Taylor ◽  
STK Vautin

From the wood of Grevillea robusta a new phenol, grevillol, was isolated in high yield, together with sitosterol. The structure of grevillol was established as 5-n-tridecylresorcinol by spectroscopic methods, chemical degradation, and synthesis. The wood of Orites excelsa yielded only sitosterol.


1981 ◽  
Vol 46 (12) ◽  
pp. 3063-3073 ◽  
Author(s):  
Jana Podlahová ◽  
Bohumil Kratochvíl ◽  
Vratislav Langer ◽  
Josef Šilha ◽  
Jaroslav Podlaha

The equilibria and mechanism of addition of protons to the ethylenediphosphinetetraacetate anion (L4-) were studied in solution by the UV, IR, 1H and 31P NMR spectroscopic methods. A total of six protons can be bonded to the anion. They are added stepwise, first with partial formation of zwitterions containing P-H bonds, which then dissociate with formation of the free acid, H4L, where all four protons are bonded in carboxyl groups. The formation of zwitterions is strongly dependent on the concentration. In the final stage, the acid bonds two additional protons to form the bis-phosphonium cation, H6L2+. A number of isostructural salts containing this cation, H4L.2 HX (X = Cl, Br, I), have been prepared. The X-ray crystal structure determination of the bromide confirmed the expected arrangement. The bromide crystals are monoclinic, a = 578.2, b = 1 425.0, c = 1 046.7 pm, β = 103.07° with a space group of P21/c, Z = 2. The final R factor was 0.059 based on 1 109 observed reflections. The structure consists of H6L2+ cations containing protons bonded to phosphorus atoms (P-H distance 134 pm) and of bromide anions, located in gaps which are also sufficiently large for I- anions in the isostructural iodide. The interbonding of phosphonium cations proceeds through hydrogen bonds, C-OH...O=C, in which the O...O distance is 275.3 pm.


1979 ◽  
Vol 34 (11) ◽  
pp. 1573-1575 ◽  
Author(s):  
Klaus Beelitz ◽  
Klaus Praefcke ◽  
Salo Gronowitz

Abstract UV irradiation of S-(3′-thienyl)2-chloro-thionicotinate (1) in benzene solution leads via dehydrohalogenation and cy clization in competition to α-cleavage to formation of thio-lactone 2 besides aldehyde 3 and disulphide 4. 2 contains a new heterocyclic ring system which has been confirmed by spectroscopic methods.


2000 ◽  
Vol 55 (9-10) ◽  
pp. 671-680 ◽  
Author(s):  
Cordula Amann ◽  
Kambiz Taraz ◽  
Herbert Budzikiewicz ◽  
Jean-Marie Meyer

Abstract The structure of the pyoverdin siderophore of Pseudomonas fluorescens 18.1 was elucidated by spectroscopic methods and chemical degradation. By cross feeding studies structurally closely related pyoverdins containing a C-terminal cyclopeptidic substructure were tested regarding the mutual recognition by the producing strains. Partial recognition of foreign pyoverdins was observed.


1985 ◽  
Vol 63 (4) ◽  
pp. 993-995 ◽  
Author(s):  
Kazimierz Antczak ◽  
John F. Kingston ◽  
Alex G. Fallis

Stereoselective total synthesis of (±)-sinularene and (±)-5-epi-sinularene are described. The sequence employs a "blocked" cyclopentadiene in which the cyclopropane unit also serves as a latent methyl group. Thus intramolecular [4 + 2] cycloaddition of the substituted methyl spiro[2.4]hepta-4,6-dien-1-yl)-2-pentenoate 11 affords 5-benzyloxy-6-isopropyl-8-carbomethoxytetracyclo[5.4.01,7.02,4.02,9]undec-10-ene (12) which after selective hydrogenolysis generates the tricyclo[4.4.01,6.02,8]decane (sinularene) ring system. Removal of the secondary hydroxyl function (Ph3P/CCl4/CH3CN; H2/Pd/C), reduction of the methyl ester (LiAlH4), and introduction of the exocyclic double bond (acetate pyrolysis, 550 °C) completes the synthesis of (±)-sinularene in 14 steps from cyclopentadiene. A parallel series of reactions employing the isopropyl epimer of 12 affords (±)-5-epi-sinularene.


1999 ◽  
Vol 54 (3-4) ◽  
pp. 156-162 ◽  
Author(s):  
Jessica Voss ◽  
Kambiz Taraz ◽  
Herbert Budzikiewicz

From the strain 51W of Pseudomonas fluorescens living under extreme conditions at the Schirmacher Oasis (Antarctica) a pyoverdin was obtained. Its structure was elucidated by chemical degradation and spectroscopic methods. The NMR data of the pyoverdin and of its Ga(III) complex were compared. Appreciable influences of the metal on the chemical shifts of the atoms at its binding sites were observed. Thus the structural elements involved in the complexation can be identified and coinciding signals of amino acids occurring more than once in the peptide chain can be separated.


1996 ◽  
Vol 51 (3-4) ◽  
pp. 139-150 ◽  
Author(s):  
E. M. Schaffner ◽  
R. Hartmann ◽  
K. Taraz ◽  
H. Budzikiewicz

Abstract Chromopeptide siderophores (azotobactin 87-1 and -II) were isolated from an iron deficient culture medium of Azotobacter vinelandii ATCC 12837 (=DSM 87). Their structures were elu­ cidated by chemical degradation studies and spectroscopic methods, especially 2D-NMR-tech-niques. Total assignments of 1H-, 13C-, and 15N-resonances based on 2D-HOHAHA-, 1H/13C-HMQC-, 1H /13C-HMBC-, 1H /15N-HMQC/TOCSY-, and 1H/15N-HMBC-experiments are given as well as sequential information derived from 1H/1H-NOESY-, 1H /13C-HMBC-and 1H/ 13N-HMBC-experiments. Both Az 87-1 and Az 87-11 consist of a tetracyclic chromophore -(1S)8,9-dihydroxy-4-oxo-2,3,4,5-tetrahydro-1H,10cH-3a,5,10b-triazaacephenantrylene-1-carb-oxylic acid -and a decapeptide chain linked with the N-terminus to the carboxy group of the chromophore containing also modified, non-proteinogenic amino acids. The sequence L-Ser-D-Ser-L-Hse-Gly-D-threo-OHAsp-Hse-Hse-Hse-D-N5OH-N5-R-Hbu-Om-L-Hse was determined for Az 87-1, while Az 87-11 contains a C-terminal L-Hse-lactone instead. Iron is chelated by the catecholic group of the chromophore, the β-hydroxy aspartic acid, and the hydroxamate function formed by N5-hydroxyornithine and R-β-hydroxybutyric acid.


1991 ◽  
Vol 46 (12) ◽  
pp. 1625-1628 ◽  
Author(s):  
Stefan Vogler ◽  
Werner Massa ◽  
Kurt Dehnicke

The reaction of tungsten hexachloride with Se4N2 leads to [WCl4(NSeCl)]2, which reacts with pyridine to form [WCl4(NSeCl)Py], and with tetraphenylphosphonium chloride to form PPh4[WCl5(NSeCl)], which was characterized by an X-ray structure determination. Space group P21, Z = 2, 1657 observed unique reflections, R = 0.074, wR = 0.061. Lattice dimensions at —80 C: a = 710.7(1), b = 2217.9(4), c = 953.6(2) pm; β = 111.93(3) . The [WCl5(NSeCl)]- ion possesses an almost linear WNSe group with bond lengths WN = 188 pm, corresponding to a double bond, and NSe = 200 pm.


2010 ◽  
Vol 5 (5) ◽  
pp. 1934578X1000500
Author(s):  
Jixun Zhan ◽  
E. M. Kithsiri Wijeratne ◽  
A. A. Leslie Gunatilaka

Biotransformation of monocillin I (1) by Beauveria bassiana ATCC 7159 was investigated. Two new derivatives 2 and 3 were isolated and identified on the basis of the spectroscopic data. Compounds 2 and 3 are synthesized by hydration at 10,11-double bond and hydrolysis of 14,15-epoxide, respectively. The R configuration of 11-OH in 2 was established by the modified 2-methoxy-2-trifluoromethylphenylacetic acid (MTPA) method. The conversion of 1 to 2 and 3 was reconstituted in an acid solution, indicating that the formation of 2 and 3 is an acid-catalyzed instead of an enzymatic process.


1992 ◽  
Vol 47 (5) ◽  
pp. 645-655 ◽  
Author(s):  
D. Sellmann ◽  
H. Schillinger ◽  
F. Knoch

Ni(II) salts and the tetradentate thioether-thiolate ligand ′S4-C2′2- (= 1,2-bis(2-mercaptophenylthio)ethane(2-)) yield [Ni(′S4-C2′)]x (1), that also forms when Na2[Ni(′S2′ )2] (′S22-′ = o-benzenedithiolate(2-)) is alkylated by 1,2-dibromoethane. In boiling pyridine 1 adds two solvent molecules and gives pseudooctahedral [Ni(pyr)2(′S4-C2′ )] (2) which was characterized by X-ray structure determination. Reaction of 1 with PMe3 yields [Ni(PMe3)(′S4-C2′)] (4). X-ray structure determination of 4 showed that the Ni center is surrounded by one P and four S atoms in a distorted tetragonal pyramid in which the P atom, one thioether S atom and both of the thiolate S atoms form the base while the second thioether S atom occupies the apical position. Reaction of 1 with n-BuLi leads to removal of the C2H4 bridge of the ′S4-C2′2- ligand and formation of Li2[Ni(′S2′)2].When [Ni(acac)2]3 is reacted with ′buS4-C2′2 (= 1,2-bis(3,5-ditertiarybutyl-2-mercaptophenylthio)ethane(2-)) which is analogous to ′S4-C2′2-, the trinuclear [Ni(′buS4-C2′)]3 (3) forms. 3 · THF was characterized by X-ray structure determination. It contains one tetrahedrally distorted and two planar [NiS4] cores that are connected via the C2H4 groups of the ligands such that a macrocycle forms. PMe3 cleaves 3 to give mononuclear [Ni(PMe3)(′buS4-C2′)] (5). Due to its lability, it was characterized only by spectroscopic methods.


Sign in / Sign up

Export Citation Format

Share Document