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 .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. 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.

The structure determination of a new cembranolide diterpene from the soft coral Lobophytum cristigalli (Coelenterata, Octocorallia, Alcyonacea)

1984 ◽  
Vol 37 (3) ◽  
pp. 545 ◽  
Author(s):  
BF Bowden ◽  
JC Coll ◽  
MSL de Costa ◽  
MF Mackay ◽  
M Mahendran ◽  
...  
Keyword(s):  
Sri Lanka ◽  
Structure Determination ◽  
Soft Coral ◽  
X Ray ◽  
X Ray Crystallography

A specimen of Lobophytum cristigalli collected in Sri Lanka afforded two cembranolide diterpenes (7E,11E,1R,2S,3R,4R,14S)-14-acetoxy-3,4-epoxycembra-7,11,15-trien-17,2-olide (6)* and the corresponding alcohol (7). Their structures were deduced spectroscopically and detailed stereochemistry of (6) was determined by X-ray crystallography.

Studies of Australian Soft Corals .XXXVI. The Isolation and Structure Determination of 11 Calamenene-Based Sesquiterpenes From Lemnalia-Cervicornis (Coelenterata, Octocorallia, Alcyonacea)

1986 ◽  
Vol 39 (1) ◽  
pp. 103 ◽  
Author(s):  
BF Bowden ◽  
JC Coll ◽  
LM Engelhardt ◽  
DM Tapiolas ◽  
AH White
Keyword(s):  
Structure Determination ◽  
Soft Coral ◽  
Soft Corals ◽  
X Ray ◽  
Chemical Correlation ◽  
Derivatives Of ◽  
Absolute Stereochemistry

The soft coral Lemnalia cervicornis May 1898 has afforded 13 novel sesquiterpenoid metabolites. The majority were derivatives of calamenen-7-ol and the structures were deduced by 1H and 13C n.m.r . spectroscopy. Absolute stereochemistry of compounds (3)-(13) was determined by chemical correlation with 7-hydroxycalamenen-3-one (3) for which an X-ray structure determination of its 7-p-bromobenzoyl derivative is reported. Two minor metabolites (15) and (16) were not aromatic, but were structurally related to the algal metabolite zonarene (21) for which absolute stereochemistry was available.

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.

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. XXXVIII. Structure Determination of Several Diterpenes Derived From a Cespitularia Species (Coelenterata, Octocorallia, Xeniidae)

1986 ◽  
Vol 39 (5) ◽  
pp. 803 ◽  
Author(s):  
BF Bowden ◽  
JC Coll ◽  
JM Gulbis ◽  
MF Mackay ◽  
RH Willis
Keyword(s):  
Structure Determination ◽  
Structure Elucidation ◽  
Soft Coral ◽  
Authentic Sample ◽  
Spectroscopic Studies ◽  
Soft Corals ◽  
X Ray ◽  
Spectral Comparison ◽  
Absolute Structure

The structure elucidation of three new diterpenes , isolated from a soft coral Cespitularia species, is reported. Two of the metabolites (3), (7E,11E,1R*,3aS*,4S*,12aR*)-11-iso-propyl-1,4,8-trimethyl- 1,2,3,3a,4,5,6,9,10,12a-decahydrocyclopentacycloundecene-1,4-diol, and (4), (4E,7E,11E)-11-isopropyl-1,4,8-trimethyl-1,2,3,3a,6,9,10,12a-octahydrocyclopentacyclo-undecen-1-ol, are shown to possess a further cyclized cembrane skeleton, the structure of (3) being determined by a single-crystal X-ray determination while that of (4) was deduced from spectral comparison with (3). The structure of the remaining diterpene (5) (4,5-deoxyneodolabelline) was deduced from 1H and 13C n.m.r . spectroscopic studies and shown to be closely related to the recently reported clavularian metabolite neodolabelline (8). An authentic sample of neodolabelline (8) was chemically transformed into (5) by the action of a zinc-copper couple establishing the absolute structure of (5).

Structure determination of lectins by x‐ray crystallography – a hands‐on approach

2013 ◽  
pp. 222-246
Author(s):  
Gabriele Cordara ◽  
Ute Krengel
Keyword(s):  
Structure Determination ◽  
X Ray ◽  
X Ray Crystallography ◽  
Hands On

scholarly journals 2-(3,5-Dimethyl-1H-pyrazol-1-yl)thiazolo[4,5-b]pyridine

Molbank ◽  
10.3390/m1077 ◽  
2019 ◽  
Vol 2019 (3) ◽  
pp. M1077
Author(s):  
Lan ◽  
Zheng ◽  
Wang
Keyword(s):  
Nmr Spectroscopy ◽  
Single Crystal ◽  
1H Nmr ◽  
Structure Determination ◽  
1H Nmr Spectroscopy ◽  
Pyrazole Ring ◽  
Hydrogen Atoms ◽  
X Ray ◽  
X Ray Crystallography

The compound 2-(3,5-dimethyl-1H-pyrazol-1-yl)thiazolo[4,5-b]pyridine (1) was synthesized with a yield of 71% by the reaction of 1-(thiazolo[4,5-b]pyridine-2-yl)hydrazine and acetylacetone. The structure was characterized by a single-crystal X-ray structure determination as well as 1H and 13C{1H} NMR spectroscopy. X-ray crystallography on 1 confirms the molecule consists of a pyridine–thiazole moiety and the pyrazole ring, and all non-hydrogen atoms are planar.

Catalyst-Free Synthesis of Diastereomerically Pure 3-Sulfonyl­azetidin-2-ones via Microwave-Assisted Tandem Wolff Rearrangement–Staudinger Cycloaddition

Synthesis ◽  
2020 ◽  
Author(s):  
Mikhail Krasavin ◽  
Judith Synofzik ◽  
Olga Bakulina ◽  
Olga Balabas ◽  
Dmitry Dar’in
Keyword(s):  
Drug Design ◽  
Single Crystal ◽  
Wolff Rearrangement ◽  
X Ray ◽  
Design And Optimization ◽  
X Ray Crystallography ◽  
Microwave Assisted ◽  
Catalyst Free ◽  
Relative Stereochemistry ◽  
Wide Range

A wide range of α-diazo-β-ketosulfones have been applied to thermally promoted tandem Wolff rearrangement – Staudinger [2+2] cycloaddition with imines to give polysubstituted β-lactam sulfones. Dia­stereomerically pure syn-diastereomers were obtained in good yields and the relative stereochemistry was confirmed by single-crystal X-ray crystallography. These findings significantly expand the scope of this transformation, in contrast to substantial limitations reported previously. Moreover, this methodology enables flexible exploration of new substitution patterns around the privileged β-lactam core for drug design and optimization.

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