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Intramolecular hydrogen bonding hydroxamic acids

The N—O—H angles for the 55 molecules in Table 2 do not require a histogram, because they range only between 100° and 103°, except for the hydroxylamine having R = H and R" = NO2, for which the angle is 104°. This remarkable uniformity is all the more noteworthy because the molecules encompass a variety of structural features, such as the C=N double bonds in the oximes and the intramolecular hydrogen bonding in the hydroxamic acids. [Pg.35]

The structures of these molecules show the effects of intramolecular electrostatic interactions. Two examples are the lone pair—lone pair repulsion that is an important determinant of hydroxylamine and oxime conformations, and the intramolecular hydrogen bonding in hydroxamic acids that promotes the near-planarities of their —C(=0)—NO frameworks. [Pg.49]

The low value for oS30 undoubtedly arises from intramolecular hydrogen bonding stabilizing the neutral form of the acid (4), a circumstance also occurring in the pyridine-2-carboxylic and -2-hydroxamic acids as well as 2-hydroxypyridine. [Pg.8]

The hydroxamic acids also all have very similar O—H bond distances, but they are slightly longer, 0.981 to 0.984 A. This can be attributed to the intramolecular hydrogen... [Pg.31]

A type 2 intramolecular /V-acylnitroso Diels-Alder reaction of hydroxamic acid 177 followed by catalytic hydrogenation of the double bond was employed for the synthesis of substituted bridged bicyclic derivative 178, as a single diastereomer (Scheme 75 <2002OL2637>). Cleavage of the N-O bond was performed by reduction with Na(Hg) amalgam and provided m-3,7-disubstituted azocane 9, as a single isomer in 80% yield. [Pg.28]


See other pages where Intramolecular hydrogen bonding hydroxamic acids is mentioned: [Pg.234]    [Pg.19]    [Pg.30]    [Pg.32]    [Pg.41]    [Pg.47]    [Pg.117]    [Pg.234]    [Pg.263]    [Pg.38]    [Pg.103]    [Pg.77]    [Pg.251]    [Pg.170]    [Pg.251]   
See also in sourсe #XX -- [ Pg.16 , Pg.19 , Pg.20 , Pg.30 , Pg.41 ]




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Acidity intramolecular hydrogen bonding

Hydrogen bond acidic

Hydrogen bond acidity

Hydrogen bond intramolecular

Hydrogen bonding hydroxamic acids

Hydrogen bonding intramolecular

Hydrogen-bonded acids

Hydroxamate

Hydroxamates

Hydroxamic acid

Intramolecular bonding

Intramolecular bonds

Intramolecular hydrogen

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