The Acid-Catalyzed Oxygen Exchange of Acetylacetone in Dioxane—Water Solutions Measured by Oxygen-17 Nuclear Magnetic Resonance

1966 ◽  
Vol 70 (4) ◽  
pp. 1328-1330 ◽  
Author(s):  
Z. Luz ◽  
Brian L. Silver
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Oxygen Exchange ◽  
Water Solutions ◽  
Acid Catalyzed ◽  
Nuclear Magnetic

Reaction of glyoxal at the ortho position of phenols. Synthesis of 5a,10b-dihydrobenzofuro[2,3-b]benzofurans and 2-(3-benzofuranyl)phenols

1967 ◽  
Vol 45 (15) ◽  
pp. 1777-1784 ◽  
Author(s):  
E. C. M. Coxworth
Keyword(s):  
Molecular Weight ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Ortho Position ◽  
Acidic Media ◽  
Nuclear Magnetic Resonance Spectra ◽  
Acid Catalyzed ◽  
Magnetic Resonance Spectra ◽  
Nuclear Magnetic

The acid-catalyzed reaction of glyoxal at the ortho position of phenols has been shown to yield, as initial products, substituted 5a,10b-dihydrobenzofuro[2,3-b]benzofurans, such structures being indicated by the nuclear magnetic resonance spectra, and confirmed in several cases by synthesis via an unambiguous route. At higher temperatures in acidic media, and in the absence of glyoxal, these initial products were converted into the corresponding 2-(3-benzofuranyl)phenols. When glyoxal was present in acidic media, the 2-(3-benzofuranyl)phenols reacted further to give unidentified products of appreciably higher molecular weight.

Stereochemistry of acid-catalyzed cleavage of 7-chloro-1-methylnortricyclene in deuterated medium; evidence for edge protonation of nortricyclenes

1980 ◽  
Vol 58 (16) ◽  
pp. 1725-1737 ◽  
Author(s):  
Nick Henry Werstiuk ◽  
Frank Peter Cappelli
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Spectroscopic Analysis ◽  
Methyl Group ◽  
Magnetic Resonance Spectroscopic Analysis ◽  
Acid Catalyzed ◽  
Nuclear Magnetic

Cleavage of 7-chloro-1-methylnortricyclene (1e) in D2SO4–DOAc yields deuterated syn-7-chloro-1-methyl-exo-2-norbornyl acetate (3a-d) (1.04 excess d per molecule) and deuterated anti-7-chloro-1-methy l-exo-2-norbornyl acetate (3b-d) (1.28 excess d per molecule) as the kinetic products. 1H and 2H nuclear magnetic resonance spectroscopic analysis of the corresponding alcohols complexed with Eu(fod)3 shows that deuterium is located endo at C-6 and in the methyl group of the syn-7-chloroacetate, endo at C-6 and C-2, at C-7, and in the methyl group of the anti-7-chloroacetate. That the deuterium at C-6 of both acetates is 80–90% stereochemically pure endo, in our view, establishes that the bond farthest removed from the electron-withdrawing chlorine is preferentially cleaved via edge deuteronation.

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