The Deoxygenation of Some Carbohydrate Diols Via the Derived Cyclic Thiocarbonate

1986 ◽  
Vol 39 (4) ◽  
pp. 699 ◽  
Author(s):  
JJ Patroni ◽  
RV Stick ◽  
LM Engelhardt ◽  
AH White
Keyword(s):  
Single Crystal ◽  
Methyl Iodide ◽  
Structure Determination ◽  
X Ray Diffraction ◽  
X Ray ◽  
Tributyltin Hydride ◽  
Diffraction Structure

The treatment of methyl 2,6-di-O-methyl-3,4-O-thiocarbonyl-β-D-galactoside with methyl iodide gives mainly the 3-deoxy-3-iodo-D-guloside , whereas the α- anomer of the above and methyl 2-O-methyl-3,4- O- thiocarbonyl-β-L-arabinoside give mainly the 4-deoxy-4-iodo-D- glycosides. An explanation is given for these and some previously reported results. As well, two of the above cyclic thiocarbonates (β-D-galacto and β-L- arabino), together with two cyclic thiocarbonates derived from methyl α-D- mannopyranoside, when treated with tributyltin hydride, gave mixtures (nearly 1:1) of products resulting from deoxygenation . Single-crystal X-ray diffraction structure determination of the β-D- galacto and the β-L- arabino cyclic thiocarbonates showed both pyranose rings to be in the 4C1 conformation.

The Synthesis of Some Compounds Containing the Selenocarbonyl Group by Using Viehe's Salt/Sodium Hydrogen Selenide: an Approach to Cyclic Selenocarbonates in the Monosaccharide Series

1988 ◽  
Vol 41 (4) ◽  
pp. 549 ◽  
Author(s):  
CM Copeland ◽  
J Ghosh ◽  
DP McAdam ◽  
BW Skelton ◽  
RV Stick ◽  
...  
Keyword(s):  
Single Crystal ◽  
Methyl Iodide ◽  
Structure Determination ◽  
X Ray Diffraction ◽  
Hydrogen Selenide ◽  
X Ray ◽  
Sodium Hydrogen ◽  
Diffraction Structure ◽  
Vicinal Diols

The treatment of various thiols, phenols and amines with Viehe's salt (Me2N+=CCl2 Cl -), followed by addition to sodium hydrogen selenide in ethanol, can lead to useful syntheses of compounds containing the selenocarbonyl group, namely selenothiocarbamates, selenodithiocarbonates, selenothiocarbonates and selenoureas . As well, the combination of Viehe's salt/sodium hydrogen selenide allows the conversion of some carbohydrate cis vicinal diols into novel cyclic selenocarbonates, and a single-crystal X-ray diffraction structure determination of one of these selenocarbonates is reported. The treatment of these selenocarbonates with methyl iodide and various phosphorus reagents is reported, as well as some unsuccessful attempts towards tellurocarbonates and telluroureas.

The Selective Monobenzylidenation of Some Monosaccharides and Their Derivatives With α,α-Dimethoxytoluene

1988 ◽  
Vol 41 (1) ◽  
pp. 91 ◽  
Author(s):  
JJ Patroni ◽  
RV Stick ◽  
BW Skelton ◽  
AH White
Keyword(s):  
Single Crystal ◽  
Structure Determination ◽  
Acid Catalyst ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Structure

The treatment of some monosaccharides and their derivatives with a,a-dimethoxytoluene and an acid catalyst in dimethylformamide at about 80° can lead to selective benzylidenation , e.g. methyl a-D- mannopyranoside gives mainly methyl 4,6-Obenzylidene-a-D-mannoside, together with two other minor monobenzylidene derivatives (2,3-) and two minor dibenzylidene derivatives (2,3:4,6-). The treatment of various other pyranoses and pyranosides is also described. As well, a 1H n.m.r . study of the acid transformation of some of the above α-D- mannosides is reported, together with a single-crystal X-ray diffraction structure determination of a novel monobenzylidene derivative, namely methyl (S)- 2,3-O-benzylidene-α-D-mannopyranoside.

Crystal structure determination of Ag2Ga by single crystal X-ray diffraction

1998 ◽  
Vol 213 (12) ◽  
Author(s):  
A. E. Gunnæs ◽  
A. Olsen ◽  
P. T. Zagierski ◽  
B. Klewe ◽  
O. B. Karlsen ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Structure Determination ◽  
Crystal Structure Determination ◽  
X Ray Diffraction ◽  
X Ray

AbstractThe crystal structure of

scholarly journals Synthesis of Silver (I) Complexes of Iminoalkyl Functionalised -Heterocyclic Carbenes

2010 ◽  
Vol 2010 ◽  
pp. 1-5 ◽  
Author(s):  
Neil A. Williams ◽  
Mahboub Merzouk ◽  
Peter B. Hitchcock
Keyword(s):  
Nmr Spectroscopy ◽  
Structure Determination ◽  
Good Yield ◽  
Heterocyclic Carbenes ◽  
Silver Bromide ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Structure ◽  
Monodentate Coordination

A range of silver iminoalkyl imidazol-2-ylidene complexes have been isolated in good yield (50%–85%) and characterised by and NMR spectroscopy. A single crystal X-ray diffraction structure determination of 1--(benzylhydrylidene-amino)-ethyl-benzyl imidazol-2-ylidene silver bromide indicated monodentate coordination of the ligand.

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).

Ab Initio Structure Determination of Quasicrystals via Single Crystal X-Ray Diffraction

2003 ◽  
Vol 805 ◽  
Author(s):  
Hiroyuki Takakura ◽  
Akiji Yamamoto ◽  
Marc de Boissieu ◽  
Taku J Sato ◽  
An Pang Tsai
Keyword(s):  
Single Crystal ◽  
Ab Initio ◽  
Structure Determination ◽  
Dimensional Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Higher Dimensional ◽  
Icosahedral Quasicrystals ◽  
Ab Initio Structure

ABSTRACTA standard approach for structure solution of ordinary crystals begins with solving the phase problem. We show that a similar procedure can be taken even in the case of quasicrystals using single crystal X-ray diffraction by applying an ab initio structure determination method called the low density elimination method. The first picture of the occupation domains, which must be specified in a higher-dimensional structure determination of quasicrystals, is obtained from a phase-reconstructed density. We present six-dimensional densities determined by this method and give their interpretation for several different types of icosahedral quasicrystals.

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