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

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).

1966 ◽  
Vol 44 (7) ◽  
pp. 759-769 ◽  
Author(s):  
Emil J. Moriconi ◽  
John P. St. George ◽  
W. F. Forbes

Infrared, ultraviolet, and nuclear magnetic resonance spectra of the following compounds are reported: 2-indanone (I), trans- and cis-hexahydro-2-indanone (V and XI), 1-chloro-2-indanone-1,3,3-d3 (III), 1-bromo-2-indanone-1,3,3-d3 (IV), 1-chloro-trans-hexahydro-2-indanone (VII), 1-bromo-trans-hexahydro-2-indanone (VIII), some deuterated forms of these compounds, 2-chlorocyclohexanone-2,6,6-d3, and 2-bromocyclohexanone-2,6,6-d3.2-Indanone and trans-hexahydro-2-indanone each display two peaks in the carbonyl infrared region with intensity ratios of approximately 40:1. The origin of these doublets is discussed.Nuclear magnetic resonance spectra were determined to indicate the presence or absence of ring mobility, and spin–spin coupling data were used to support some of the conclusions deduced from the infrared data for some of the compounds.


1967 ◽  
Vol 45 (5) ◽  
pp. 481-494 ◽  
Author(s):  
U. G. Nayak ◽  
M. Sharma ◽  
R. K. Brown

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.


Author(s):  
V. V. Terskikh ◽  
I. L. Moudrakovski ◽  
C. I. Ratcliffe ◽  
J. A. Ripmeester ◽  
C. J. Reinhold ◽  
...  

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