Acetals nuclear magnetic resonance

C Nuclear magnetic resonance spectrum, acetaldehyde, 732 acetophenone, 732 anisole, 672 benzaldehyde, 732 benzoic acid, 771 p-bromoacetophenone, 449 2-butanone, 449, 732 crotonic acid. 771 cyclohexanol, 634 cyclohexanone, 732 ethyl benzoate, 477 methyl acetate, 443 methyl propanoate, 450 methyl propyl ether, 672... 

To illustrate the utility of the MWBD method, a series of commercial polyvinyl acetates and low density polyethylenes are analyzed. Either kinetic models or 13c nuclear magnetic resonance results are used to estimate the branching structural parameter. 

Online detection using 4H nuclear magnetic resonance (NMR) is a detection mode that has become increasingly practical. In a recent application, cell culture supernatant was monitored on-line with 1-dimensional NMR for trehalose, P-D-pyranose, P-D-furanose, succinate, acetate and uridine.33 In stopped-flow mode, column fractions can also be analyzed by 2-D NMR. Reaction products of the preparation of the neuromuscular blocking compound atracurium besylate were separated on chiral HPLC and detected by 4H NMR.34 Ten isomeric peaks were separated on a cellulose-based phase and identified by online NMR in stopped-flow mode. 

K. Nicolay, K. J. Hellingwerg, R. Kaptein, W. N. Konings (1982) Carbon-13 nuclear magnetic resonance studies of acetate metabolism in intact cells of Rhodopsedomonas sphaeroides, Biochimica etBiophysiea Acta, 250-258... 

Four kauranes present in the petroleum ether/ethyl acetate fractions of nemoralis were fully characterized by mass spectrometry, nuclear magnetic resonance spectrometry and infrared as (-)-kaur-16-en-19-oic acid, (-)-kauran-16 <-ol, 15sC-hydroxy-(-)-kaur-16-en-19-oic acid and 17-hydroxy-(-)-kaur-15-en-19-oic acid... 

The C nuclear magnetic resonance spectrum of cortisone acetate was obtained on a Joel FT 100 MHz spectrometer system, using tetramethylsilane as the internal reference. To obtain the spectrum, the substance was dissolved in CDCI3. The full C-NMR spectrum is shown in Figure 8, and assignments for the observed resonance bands are provided in Table 5. 

Figure 5. Full h nuclear magnetic resonance spectrum of cortisone acetate. 

Elsewhere, the reaction of styrene with nitrones derived from cyclic acetals of D-erythrose (e.g., 126) or D-threose has afforded a mixture of diastereomeric isoxazolidines (Scheme 1.28) (170,171). In all cases, nuclear magnetic resonance (NMR) analysis suggests that the major product contains the C(3)/C(4 ) erythro... 

In fact, the first saturated pseudoxazolone reported, 4-methyl-2-(trifluoro-methyl)-5(2//)-oxazolone, was incorrectly assigned as the tautomeric 5(4//)-oxazolone and only later did nuclear magnetic resonance (NMR) smdies establish the correct structure. This compound was synthesized from alanine and trifluoro-acetic anhydride (TFFA). This methodology constitutes, under standard conditions, the most general procedure for the synthesis of 5(2//)-oxazolones. 

Nimz, H. H., and Ludemann, H. D., 1976, Carbon 13 nuclear magnetic resonance spectra of lignins 6. Lignin and DHP acetates. Holzforsch. 30 33-40. 

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