THE STRUCTURE OF RYANODINE. I

1951 ◽  
Vol 29 (11) ◽  
pp. 905-910 ◽  
Author(s):  
R. B. Kelly ◽  
D. J. Whittingham ◽  
K. Wiesner

Ryanodine consumes one mole of periodic acid and gives oxoryanodine C25H33O9N. Splitting off water from ryanodine gives anhydroryanodine C25H33O8N. The analyses of these two derivatives are therefore in agreement with the formula for ryanodine C25H35O9N. Alkaline hydrolysis of ryanodine gives pyrrole-α-carboxylic acid and an alcohol C20H32O8. This alcohol splits off water to give a compound C20H30O7. Alkaline hydrolysis of oxoryanodine consumes three moles of alkali and gives a mixture of low molecular acidic products. Alkaline fusion of oxoryanodine gives a neutral aromatic nitrogen-free crystalline substance.

1971 ◽  
Vol 49 (17) ◽  
pp. 2797-2802 ◽  
Author(s):  
D. E. Horning ◽  
G. Lacasse ◽  
J. M. Muchowski

The sulfuric acid catalyzed acylation of 2-methyl-5-nitroisocarbostyril with carboxylic acid anhydrides gave the corresponding 4-acylated derivatives 3, which underwent reductive cyclization to 2-substituted derivatives of 4-methyl-1,3,4,5-tetrahydropyrrolo[4.3.2.de]isoquinolin-5-one (4). Alkaline hydrolysis of the six-membered lactam in 4 was accompanied by a retro-Mannich reaction to produce 2-substituted indole-4-carboxylic acids in about 40 % overall yield from 3.


1993 ◽  
Vol 71 (11) ◽  
pp. 1841-1844 ◽  
Author(s):  
Judy E. Douglas ◽  
Grant Campbell ◽  
Donald C. Wigfield

The preparation and alkaline hydrolysis of 18O-methyl 2,2-dimethylpropanoate and 18O-methyl triphenylacetate are reported. From mass spectral analysis of the carboxylic acid products, it is concluded that the former substrate is hydrolyzed exclusively by the BAC2 mechanism, whereas the latter substrate proceeds 95% by the BAC2 mechanism and 5% by the BAL2 mechanism. The balance between these two mechanisms is discussed.


1986 ◽  
Vol 64 (6) ◽  
pp. 1170-1172 ◽  
Author(s):  
Michael J. McGlinchey ◽  
Hao Nguyen

The attempted basic hydrolysis of the ester sandwich compound (C6H6)Cr(C6F5CO2Et) did not yield the expected carboxylic acid but instead produced (C6H6)Cr(C6F5H) in good yield together with traces of (C6H6)Cr(C6HF4OMe). Attempts to trap a benzyne intermediate were unsuccessful and the mechanism of decarboxylation is discussed in terms of internal chelation at the chromium centre.


1986 ◽  
Vol 51 (7) ◽  
pp. 1512-1531 ◽  
Author(s):  
Maria K. Spassova ◽  
Antonín Holý ◽  
Milena Masojídková

Bis(trimethylsilyl) derivative of ethyl 3-aminopyrazole-4-carboxylate (VI) and tris(trimethylsilyl) derivative of ethyl 3,5-diaminopyrazole-4-carboxylate (VII) on reaction with 2,3,5-tri-O-benzoyl-D-ribofuranolyl chloride and subsequent debenzoylation afforded the respective β-D-ribofuranosyl derivatives VIIIa and Xa. Their alkaline hydrolysis led to 1-(β-D-ribofuranosyl)-3-aminopyrazole-4-carboxylic acid (VIIIc) and 1-(β-D-ribofuranosyl)-3,5-diaminopyrazole-4-carboxylic acid (Xb). The esters VIIIa and Xa were not ammonolyzed under normal conditions. Contrary to nucleosidation of the silyl derivatives VI and VII, sodium salt of ethyl 3-aminopyrazole-4-carboxylate was alkylated with 4-chloromethyl-2,2-dimethyl-1,3-dioxolane (XI) or 5-(p-toluenesulfonyloxy)-1,3-dioxane (XVIIb) to give a mixture of the N-isomeric derivatives XIIIa, XIXa and XIIa, XVIIIa, respectively; sodium salt of the 3,5-diamino derivative V reacted with these synthons under formation of the corresponding compounds XIIIb and XXa. Subsequent alkaline and acid hydrolysis of XIIa and XIIIb gave the open-chain analogs of nucleosides XV and XVI. The N-(1,3-dioxan-5-yl) derivatives XVIIIc and XXa resisted acid hydrolysis, giving rise only to carboxylic acids XVIIIb and XXb.


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