Stepwise synthesis of selenium coronands containing an odd number of selenium atoms: 1,5,9-triselenacyclododecane and 1,5,9,13,17-pentaselenacycloeicosane

1995 ◽  
Vol 73 (1) ◽  
pp. 113-116 ◽  
Author(s):  
Ivan Cordova-Reyes ◽  
Elizabeth VandenHoven ◽  
Ali Mohammed ◽  
B. Mario Pinto
Keyword(s):  
Liquid Ammonia ◽  
Metal Reduction ◽  
Selenium Atom ◽  
Stepwise Synthesis ◽  
Sodium Metal

The stepwise synthesis of two new selenium coronands containing an odd number of selenium atoms, starting from the fragments HO-(CH2)3-Cl, HO-(CH2)3-Br, HO-(CH2)3-SeCN, and NCSe-(CH2)3-SeCN, is described. The key diol containing one selenium atom, 4-selenaheptan-1,7-diol 4, was obtained in 97% yield from the reaction of 3-bromo-1-propanol 3 and the selonolate anion derived from 3-selenocyanato-1-propanol 2 by sodium metal reduction in liquid ammonia. The ditosylate 5, obtained from 4, was then treated with the bisselenolate anion derived from 1,3-bisselenocyanatopropane 6 to give the target selenium coronand, 1,5,9-triselenacyclododecane [12Se3] 7, in 96% yield. The ditosylate 5 was treated with two equivalents of the selenolate anion derived from 2 to give a second key acyclic diol 8 now containing three selenium atoms. The ditosylate 9, obtained from 8, was then treated with the bisselenolate anion derived from 6 to afford the second target coronand, 1,5,9,13,17-pentaselenacycloeicosane [20Se5] 11 in 44% yield. Keywords: selenium coronands, stepwise synthesis, macrocycles, heterocycles.

3-deoxygenation of methyl α--glucopyranosides by treatment of their 3--(,-dimethylsulfamoyl) derivatives with sodium metal in liquid ammonia

1978 ◽  
Vol 19 (36) ◽  
pp. 3365-3368 ◽  
Author(s):  
Tsutomu Tsuchiya ◽  
Isamu Watanabe ◽  
Masao Yoshida ◽  
Fujio Nakamura ◽  
Takayuki Usui ◽  
...  
Keyword(s):  
Liquid Ammonia ◽  
Sodium Metal

Reductive cleavage with metal in liquid ammonia. II. Olefin formation in attempts at selective cleavage of methyl S-benzyl-4,6-O-benzylidene-3-O-methyl-2-thio-α-d-altropyranoside and its S-methyl analogue by sodium metal in liquid ammonia diluted with 1,2-dimethoxyethane

1967 ◽  
Vol 45 (5) ◽  
pp. 481-494 ◽  
Author(s):  
U. G. Nayak ◽  
M. Sharma ◽  
R. K. Brown
Keyword(s):  
Liquid Ammonia ◽  
Mixed Solvent ◽  
Reductive Cleavage ◽  
Metallic Sodium ◽  
Reaction Conditions ◽  
Sodium Metal ◽  
Alkaline Reaction

When methyl S-benzyl-4,6-O-benzylidene-3-O-methyl-2-thio-α-d-altropyranoside (VI) in liquid ammonia was treated with metallic sodium, a reductive cleavage occurred to give methyl 3-O-methyl-2-thio-α-d-altropyranoside in an 85% yield. In the solvent 1,2-dimethoxy-ethane, the reaction of sodium with VI gave little, if any, reductive cleavage. Instead, a base-catalyzed elimination of methanol took place to give the two olefins methyl,S-benzyl-4,6-O-benzylidene-2,3-didehydro-3-deoxy-2-thio-α-d-erythro-hexopyranoside (IX) and S-benzyl-4,6-O-benzylidene-l,2-didehydro-1-deoxy-3-O-methyl-2-thio-d-ribo-hexopyranose (X). Under the alkaline reaction conditions, IX isomerized partly to a third olefin, methyl.S-benzyl-4,6-O-benzylidene-3,4-didehydro-3-deoxy-2-thio-α-d-erythro(threo)-hexopyranoside (XI).In the mixed solvent liquid ammonia and 1,2-dimethoxyethane, sodium reacted with VI to give a 33% yield of the 2,3-olefin IX. Other products, no doubt present, were not isolated in this experiment.Three analogous olefins were obtained from the reaction of sodium or basic reagents with methyl 4,6-O-benzylidene-3-O,S-dimethyl-2-thio-α-d-altropyranoside (VIa) in 1,2-dimethoxyethane.

X-ray diffraction study of sodium metal reduction tantalum powders

2013 ◽  
Vol 50 (1) ◽  
pp. 46-51 ◽  
Author(s):  
V. M. Orlov ◽  
R. N. Osaulenko ◽  
D. N. Malyshevsky ◽  
V. N. Kolosov ◽  
T. Yu. Prokhorova ◽  
...  
Keyword(s):  
Diffraction Study ◽  
Metal Reduction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sodium Metal

scholarly journals Anionic Oligomerization of Styrenein Liquid Ammonia Catalized by Sodium Metal

1964 ◽  
Vol 67 (6) ◽  
pp. 939-944
Author(s):  
Eishun Tsuchida ◽  
Isao Shinohara ◽  
Shu Kambara ◽  
Takao Kawamura ◽  
Akikazu Takahashi
Keyword(s):  
Liquid Ammonia ◽  
Sodium Metal

Deoxygenation of sugar trifluoromethanesulfonates by sodium metal in liquid ammonia and by photolysis

1979 ◽  
Vol 20 (30) ◽  
pp. 2805-2808 ◽  
Author(s):  
Tsutomu Tsuchiya ◽  
Fujio Nakamura ◽  
Sumio Umezawa
Keyword(s):  
Liquid Ammonia ◽  
Sodium Metal

Reductive cleavage with metal in liquid ammonia. III. Olefin formation from the reaction of sodium metal with methyl 4,6-O-ethylidene-3-O,S-dimethyl-2-thio-α-d-altropyranoside dissolved in 1,2-dimethoxyethane

1967 ◽  
Vol 45 (15) ◽  
pp. 1767-1775 ◽  
Author(s):  
U. G. Nayak ◽  
M. Sharma ◽  
R. K. Brown
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Liquid Ammonia ◽  
Reductive Cleavage ◽  
Metallic Sodium ◽  
Sodium Metal ◽  
Infrared Data ◽  
Nuclear Magnetic

Methyl 4,6-O-ethylidene-3-O,S-dimethyl-2-thio-α-d-altropyranoside, when heated in refluxing 1,2-dimethoxyethane with an equimolar quantity of metallic sodium, gave approximately a 75% yield of a mixture of the three olefins, methyl 2,3-didehydro-3-deoxy-4,6-O-ethylidene-S-methyl-2-thio-α-d-altropyranoside (XI), l,2-didehydro-l-deoxy-4,6-O-ethylidene-3-O,S-dimethyl-2-thio-d-ribo-hexopyranose (XII), and methyl 3,4-didehydro-3-deoxy-4,6-O-ethylidene-S-methyl-2-thio-α-d-erythro(or threo)-hexopyranoside (XIII) (tentative). Only compounds XI and XII could be separated and characterized. The structural assignments were based on a comparison with authentic samples and on nuclear magnetic resonance and infrared data, as well as on a comparison with the characteristics of analogous 4,6-O-benzylidene compounds previously reported (2).

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