Studies of Australian Soft Corals. XLII. Structure Determination of New Briaran Derivatives From Briareum steckei (Coelenterata, Octocorallia, Gorgonacea)

1987 ◽  
Vol 40 (12) ◽  
pp. 2085 ◽  
Author(s):  
BF Bowden ◽  
JC Coll ◽  
W Patalinghug ◽  
BW Skelton ◽  
I Vasilescu ◽  
...  
Keyword(s):  
Single Crystal ◽  
High Field ◽  
Soft Corals ◽  
X Ray ◽  
Relative Stereochemistry ◽  
Minor Metabolite ◽  
A Minor ◽  
New Compounds ◽  
New Metabolites

The structure and relative stereochemistry of four new metabolites from Briareum steckei has been deduced from 2D-n.m.r. experiments at high field, and confirmed by a single-crystal X-ray determination of a minor metabolite. The new compounds are non-halogenated briaran derivatives: (1R*,2S*,3R*,5Z,7S*,8(17)Z,l0R*, llR *,12S*,14S*)- 3,14-diacetoxy- 11,12-epoxy- 18-oxobriara-5,8(17)-dien-2-yl butanoate (3), its 3-deacetoxy derivative (4), (1R*,2R*,4R*,5Z,7S*,8(17)Z,10R*, 11R *,12S*,14S*)-4,14-diacetoxy-11,12-epoxy-18-oxobriara-5,8(17)-dien-2-yl butanoate (5) and the related 2-propanoate (6). Single-crystal X-ray determinations were performed on (5) and (6).

Studies of Australian soft corals. XXXII. The structure determination of degraded xenicin-type diterpenes from several Efflatounaria species

1983 ◽  
Vol 36 (11) ◽  
pp. 2279 ◽  
Author(s):  
BF Bowden ◽  
JC Coll ◽  
VA Patrick ◽  
DM Tapiolas
Keyword(s):  
Single Crystal ◽  
Chemical Transformation ◽  
Structure Determination ◽  
High Field ◽  
Soft Corals ◽  
X Ray ◽  
The Third

Three new diterpenes have been isolated from soft corals of the genus Efflatounaria (Coelenterata, Octocorallia, Alcyonacea, Xeniidae). The structure of the first compound (4) was elucidated on the basis of high-field 1H n.m.r. spectroscopy while that of the second metabolite (5) was determined by single-crystal X-ray analysis. The third diterpene (6) was structurally related to (5), and its structure was confirmed by chemical transformation. All three diterpenes can be derived from xenicin-type precursors, by cleavage and recyclization.

Studies of Australian Soft Corals. XLI. Structure Determination of a New Sesquiterpene From Xenia novae-britanniae and an Investigation of a Xenia Species

1987 ◽  
Vol 40 (8) ◽  
pp. 1483 ◽  
Author(s):  
BF Bowden ◽  
JC Coll ◽  
LM Engelhardt ◽  
A Heaton ◽  
AH White
Keyword(s):  
Single Crystal ◽  
Structure Determination ◽  
Soft Coral ◽  
Soft Corals ◽  
X Ray ◽  
X Ray Crystallography ◽  
Relative Stereochemistry

.A novel sesquiterpene (1 Z,2R*,4R*,7S*,11S*)-3,3,7,11-tetramethyltricyclo[6.3.0.02,4]undec-1(8)-en-4-ol (3) was isolated from the soft coral Xenia novae-britanniae. Its structure was tentatively deduced by n.m.r. spectroscopy, and the structure with relative stereochemistry was confirmed by single-crystal X-ray crystallography. Investigation of a Xenia species afforded the known metabolite waixenicin -A previously isolated from Anthelia edmondsoni .

Studies of Australian soft corals. XXVIII. The structure determination of two new diterpenes from the genus Xenia (Alcyonacea)

1982 ◽  
Vol 35 (5) ◽  
pp. 997 ◽  
Author(s):  
BF Bowden ◽  
JC Coll ◽  
E Ditzel ◽  
SJ Mitchell ◽  
WT Robinson
Keyword(s):  
Single Crystal ◽  
Structure Determination ◽  
Soft Corals ◽  
X Ray

The isolation of '9-deacetoxyxenicin' [systematic name: (1R*,4aS*,7E,11aS*,1'R*,2'R*)-1-acetoxy-4-(1',2'-diacetoxy-4'-methylpent-3'-enyl)-7-methy1-11-methylene-1,4a,5,6,9,10,11,11a-octahydrocyclonona[c]pyran] (2) from Xenia crassa and a further cyclized diterpene (6) from Xenia viridis are described. The structure of (2) was derived from n.m.r. spectroscopic comparison with xenicin (1), whilst the structure of (6) was determined by a single-crystal X-ray analysis when spectroscopy failed to afford an unambiguous structure.

Tropical Marine Algae. V. The Structure Determination of Two Novel Sesquiterpenes From the Red Alga Laurencia tenera (Rhodophyceae, Ceramiales, Rhodomelaceae)

1989 ◽  
Vol 42 (10) ◽  
pp. 1695 ◽  
Author(s):  
JC Coll ◽  
BW Skelton ◽  
AH White ◽  
AD Wright
Keyword(s):  
Single Crystal ◽  
Structure Determination ◽  
High Field ◽  
Marine Algae ◽  
Red Alga ◽  
X Ray Diffraction ◽  
X Ray

Laurencia tenera has been shown to contain two novel sesquiterpenes. The structure of the less abundant metabolite (3) was determined by single-crystal X-ray diffraction as (1S,2R,4S,5R,6R,8S,9R)-4,8-dibromo-2,5,6,9-tetramethyltricyclo[7.2.0.01.6] undecane-3-one.‡ The more abundant, but less stable metabolite (4) was investigated by extensive high-field N.M.R. spectroscopy. Its structure is proposed as (1S*,2R*,4R*,5R*,6R*,8R*)-4-bromo-2,5,6-trimethyl-11-methylenetricyclo[6.2.1.01.6]undecan-3-one.§ The sesquiterpene (3) is isomeric with the known metabolite perforatone (5).

Studies of Australian Soft Corals .XXXVII. The Structure Determination of 2 Cembranolide Diterpenes From Soft Corals of the Genus Efflatounaria (Coelenterata, Octocorallia, Alcyonacea)

1986 ◽  
Vol 39 (1) ◽  
pp. 123 ◽  
Author(s):  
BF Bowden ◽  
JC Coll ◽  
LM Engelhardt ◽  
GV Meehan ◽  
GG Pegg ◽  
...  
Keyword(s):  
Structure Determination ◽  
Soft Coral ◽  
Soft Corals ◽  
X Ray ◽  
X Ray Crystallography ◽  
Coral Genus ◽  
Relative Stereochemistry ◽  
Chemical Correlation ◽  
Absolute Stereochemistry

Two isomeric 7,8-epoxycembra-3,11,15-trien-16,2-olides have been isolated from different species of the soft coral genus Efflatounaria. The structure of each was deduced spectroscopically , and the relative stereochemistry of one was determined by X-ray crystallography. The absolute stereochemistry of each cembranolide was obtained by chemical correlation with known compounds.

Studies of Australian Soft Corals. XLVI. New Diterpenes From a Briareum Species (Anthozoa, Octocorallia, Gorgonacea)

1989 ◽  
Vol 42 (10) ◽  
pp. 1705 ◽  
Author(s):  
BF Bowden ◽  
JC Coll ◽  
IM Vasilescu
Keyword(s):  
High Field ◽  
Nuclear Overhauser Effect ◽  
Soft Corals ◽  
Overhauser Effect ◽  
Relative Stereochemistry ◽  
Nuclear Overhauser ◽  
New Compounds

The structures and relative stereochemistry of nine new briaran -based diterpenes from a Briareum species have been deduced from 2-D n.m.r. experiments at high field, and nuclear Overhauser effect experiments. The new compounds are (1R*2R*,3R*,5Z,7S*,8S*,9S*,10S*,11R*,-12S*,14S*,17R*)-2,3,14-triacetoxy-8,17:11,12-bisepoxy-9-hydroxybriar-5-en-18-one (5), (1R* ,2R* ,3R* ,5Z*,7S*,8S* ,9S*,10S*,11R*,12S*, 14S*, 17R*)-3,14-diacetoxy-2-butyryloxy-8,17:11,12-bisepoxy-9-hydroxybriar-5-en-18-one (6),(1R*,2R*,3R*,5Z,7S*,8S*,9S*,10S*,11R*,12S*,14S)-2,3,14-triacetoxy-11,12-epoxybriara-5,8(17)-dien-18-one(17),(1S*,2S*,4R*,5Z,7S*,8S*,9S*,10S*,2,4,9.12-tetraacetoxy-8,17-epoxy-11-hydroxybriara-5,13-dien-18-one (8),(1S*, 2S*,4R*, 5Z,7S*,8S*,9S*,10S*, 11S*, 12R*,13Z,17R*)-2,4,9-triacetoxy-8,17-epoxy-11,12-dihydroxybriara-5,13-dien-18-one (9), (1S *,2S*,4R*,5Z,7S*,8S*,9S*,10S*, 11S *,12R*,13Z,17R*)-2,4,9,12-tetraacetoxy-8,17-epoxy-11-hydroxybriara-5,13-dien-18-one(10),(1Si,2S*,5Z,7S',8S*,-9S*,10S*,11R*,12R*,13Z,17R*)-2,12-diacetoxy-8,17-epoxy-9-hydroxybriara-5,13-dien-18-one(ll), (1R*,2R*,3Si,5Z,7S* ,8S* ,9S* ,10S* ,11Z,14S*,17R*)-2,14-diacetoxy-3-butyryloxy-8,17-epoxy-9-hydroxybriara-5,11-dien-18-one (12) and (1R *,2R*,3S*,5Z,7S*,8S*,9S*,10S*,11Z,-14S',17R*)-2,3,14-triacetoxy-8,17-epoxy-9-hydroxybriara-5,11-dien-18-one (13). In addition to the nine new briaran derivatives, the same coral afforded two cladiellane derivatives (1R*,4R*,5S*,6R*,8R*,12R*,13R*,14R*)-cladiellane-4,8,12-triol (14) and its 4-acetoxy derivative (15). Aknowncembranoid diterpene (1R *,4R*,ZE,7E,l1E)-cembra-2,7,11-trien-4-ol(21) wasalso isolated together with an unprecedented perhydrophenanthrene-based diterpene (20): (1R *, 1aR*,4S*,4aR*,5aR*,8aR*)-4-isopropyl-l,8a-dimethyl-5-methylenetetradecahydrophenanthren-1-ol. The extraordinary biosynthetic ability of soft corals from the genus Briareum is once more revealed.

Single Crystal Growth of High-Pressure Phases of Ice and Salt Hydrate Far Below the Original Melting Point by Mixing Alcohol: Crystal Structure Determination of Magnesium Chloride Heptahydrate

2020 ◽  
Author(s):  
Keishiro Yamashita ◽  
Kazuki Komatsu ◽  
Hiroyuki Kagi
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Crystal Growth ◽  
Single Crystal ◽  
Room Temperature ◽  
Growth Technique ◽  
Salt Hydrate ◽  
X Ray

An crystal-growth technique for single crystal x-ray structure analysis of high-pressure forms of hydrogen-bonded crystals is proposed. We used alcohol mixture (methanol: ethanol = 4:1 in volumetric ratio), which is a widely used pressure transmitting medium, inhibiting the nucleation and growth of unwanted crystals. In this paper, two kinds of single crystals which have not been obtained using a conventional experimental technique were obtained using this technique: ice VI at 1.99 GPa and MgCl<sub>2</sub>·7H<sub>2</sub>O at 2.50 GPa at room temperature. Here we first report the crystal structure of MgCl2·7H2O. This technique simultaneously meets the requirement of hydrostaticity for high-pressure experiments and has feasibility for further in-situ measurements.

Two lithium tricyanomethanide compounds: syntheses and single-crystal structure determination of LiK[C(CN)3]2 and Li[C(CN)3]·½ (H3C)2CO

2015 ◽  
Vol 70 (3) ◽  
pp. 191-196 ◽  
Author(s):  
Olaf Reckeweg ◽  
Francis J. DiSalvo
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Single Crystals ◽  
Structure Determination ◽  
Monoclinic Space Group ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
Cell Parameters ◽  
New Compounds

AbstractThe new compounds LiK[C(CN)3]2 and Li[C(CN)3]·½ (H3C)2CO were synthesized and their crystal structures were determined. Li[C(CN)3]·½ (H3C)2CO crystallizes in the orthorhombic space group Ima2 (no. 46) with the cell parameters a=794.97(14), b=1165.1(2) and c=1485.4(3) pm, while LiK[C(CN)3]2 adopts the monoclinic space group P21/c (no. 14) with the cell parameters a=1265.7(2), b=1068.0(2) and c=778.36(12) pm and the angle β=95.775(7)°. Single crystals of K[C(CN)3] were also acquired, and the crystal structure was refined more precisely than before corroborating earlier results.

Synthesis of 4-(3-coumarinyl)-3-benzyl-4-thiazolin-2-one 4-methylbenzylidenehydrazone and determination of the isomeric structure by X-ray analysis

2003 ◽  
Vol 218 (12) ◽  
Author(s):  
Süheyla Özbey ◽  
Nilgün Karalı ◽  
Aysel Gürsoy
Keyword(s):  
Single Crystal ◽  
Diffraction Analysis ◽  
Spectral Data ◽  
X Ray Diffraction ◽  
X Ray ◽  
Isomeric Structure ◽  
Elemental Analyses

AbstractIn this study 4-(3-coumarinyl)-3-benzyl-4-thi azolin-2-one 4-methylbenzylidenehydrazone 3 was synthesised. An independent proof of the thiazolylhydrazone structure of 3 was achieved by single crystal X-ray diffraction analysis. Elemental analyses and spectral data (IR,

Bis[dicarbonyl(cyclopentadienyl)ruthenium(I)] Komplexe / Bis[dicarbonyl(cyclopentadienyl)ruthenium(I)] Complexes

2002 ◽  
Vol 57 (9) ◽  
pp. 1017-1026 ◽  
Author(s):  
Herbert Schumann ◽  
Susanne Stenz ◽  
Frank Girgsdies ◽  
Stefan H. Mühle
Keyword(s):  
Single Crystal ◽  
Nmr Spectra ◽  
X Ray ◽  
Tert Butyl ◽  
New Compounds ◽  
C Nmr

Ru3(CO)12 reacts with 1-tert-butyl-2,4-cyclopentadiene (1), 1-trimethylsilyl-2,4-cyclopentadiene (2), 1-tert-butyl-3-methyl-2,4-cyclopentadiene (3), 1,3-di(tert-butyl)-2,4-cyclopentadiene (4), 1-iso-propyl-2,3,4,5-tetramethyl-2,4-cyclopentadiene (5), 1-tert-butyl-2,3,4,5-tetramethyl- 2,4-cyclopentadiene (6), 1-phenyl-2,3,4,5-tetramethyl-2,4-cyclopentadiene (7), 2,5- diphenyl-2,4-cyclopentadiene (8), or 2,3,4,5-tetraphenyl-2,4-cyclopentadiene (9) with formation of the corresponding bis[dicarbonyl(cyclopentadienyl) ruthenium(I)] complexes [RuCp# (CO)2]2 1a to 9a. The 1H and 13C NMR spectra of the new compounds 3a and 5a to 9a as well as the single crystal X-ray structures of 1a, 4a, 5a, 7a, 8a, and 9a are reported and discussed

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