acetolysis in Czech

acetolýza Entry edited by: B2

Sentence patterns related to "acetolysis"

1. Benzenesulfonyl aziridines of these compounds were prepared and their acetolysis was studied.

2. All but the intine become acetolysis resistant indicating the presence of sporopollenin.

3. Acetolysis of the reduced gum afforded a mixture of oligosaccharide acetates.

4. The volume of activation for acetolysis of uncomplexed ester was −27 cm3 mol−1 while that for acetolysis of the 1:1 complex was −33 cm3 mol−1, relative to uncomplexed reactants.

5. At maturity these spines are affected differently by acetolysis: microspines contain polysaccharides as well as sporopollenin, and macrospine contain only sporopollenin.

6. Acetolysis of 1-OTf-1-14C in the presence of added NaN3 or NaN3 and NaOAc, however, gave results indicating differences in behaviors between 1-OTf and 1-OTs and it is concluded that the acetolysis of 1-OTf and 1-OTs are mechanistically similar but not identical.

7. When the widely used, but chemically less appropriate acetolysis method was applied to either entire cells or isolated but not fully extracted cell walls of Coccomyxa, Elliptochloris, Myrmecia, Pseudochlorella, Trebouxia, and Trentepohlia species, they all yielded acetolysis-resistant residues whose infrared spectra resembled natural sporopollenin.

8. During maturation the sporopollenin framework of the capitula and foveolate layer become obscured by the addition of electron-dense, non-acetolysis-resistant materials.

9. About 20 and 50% rearrangements of the 13C-label from C-2 to C-1 were found, respectively, for the acetolysis and trifluoroacetolysis.

10. Nucleophilic replacement of its 8-bromo-substituent by acetolysis or methanolysis occurs with simultaneous migration, resulting in the 4-acetoxy- or 4-methoxy-compounds, respectively.

11. The analysis of the pollen residues was performed by pulverizing the sediments used to construct the cells, followed by the application of the acetolysis method.

12. The reaction products showed rearrangements of the 14C-label from C-2 to C-1 averaging about 6.7, 7.7, and 27.0%, respectively, for the acetolysis, formolysis, and trifluoroacetolysis.

13. Acetolysis of the 4,8-dibromo-1-carboxylic acid or its methyl ester occurs exclusively at the 8-position, but hydrazinolysis removes both halogen substitutents, with formation of 4-hydrazono-diisophorones.

14. Acetolysis of the product 2 afforded a mixture of anomeric triacetates 3 from which the corresponding 3,6-di-O-acetyl-2,4-O-benzyl-α-D-glucopyranosyl chloride (4) was prepared.

15. The results also showed that the boron complexes derived from Schiff bases undergo an acetolysis reaction to give the corresponding dioxazaborocines containing all substituents on the same side also in good yields.

16. On acetolysis, the wall materials that separate or surround the various openings on the germ furrow region dissolve and a characteristic narrow continuous opening (referred to as the slit) becomes visible.

17. Controlled acetolysis of 4 gave 1,2-di-O-acetyl-3,4-di-O-benzyl-α-L-rhamnopyranose (10), which upon reaction with 4 under catalysis by trimethylsilyl trifluoromethanesulfonate (TMS-Tf) yielded the α-(1 → 2)-linked dirhamnoside.

18. The carbon-13 magnetic resonance (c.m.r.) spectra of oligosaccharides, derived from yeast mannans by partial acetolysis, contain signals at δC 93.1–105.4 (C-l's) and 79.2–81.2 (C-2's and/or C-3's substituted by mannopyranosyl units).

19. The acetolysis of trans-1,2-diphenyl-2-phenylthiol[1-13C]vinyl tosylate (2-OTs-1-13C) under anhydrous conditions (HOAc–Ac2O–NaOAc) gave trans-1,2-diphenyl-2-phenylthio[1,2-13C]vinyl acetate (2-OAc-1,2-13C) as product.

20. The pollen morphology of seven species, varieties and forms of Cupressaceae from eastern Canada and northeastern United States was studied by light microscopy, following acetolysis, to improve the identification of these taxa in Quaternary fossil sediments.

21. Analysis of the acetolysis products revealed in fact the release esentially of phosphorylated mannotriose and mannotetraose units by the flocculating yeast phosphopeptidomannans, while polymers of the nonflocculating yeast were characterized by the presence of mannobiose units.

22. Hydrolysis and acetolysis of 8-bromo-1-hydroxydi-isophor-2(7)-en-3-one yields both epimeric forms of the corresponding 4-hydroxy and 4-acetoxy-compounds, probably by a mechanism involving a bimolecular (SN2′′) displacement.

23. This may indicate that silicon is an important elemental component of exine materials characteristic of many types of pollen, in which silicate compounds may aid in the high degree of pollen resistance to geological weathering, microbial decay, and acetolysis treatments.

24. Treatment with alkali converts the 6,8-dibromo-ketol, by a simultaneous 8-substitution and ring A-aromatisation, into 6-methyl-5-nordiisophora-2(7),3,5-triene-1,3,8-triol; acetolysis and methanolysis produce the corresponding 8-acetoxy- and 8-methoxy-compounds.

25. In contrast to the involvement of equilibrating protonated methylcyclopropane intermediates observed in the trifluoroacetolysis of [1-14C]-1-butyl tosylate, the present results indicated that protonated methylcyclopropane intermediates did not play a significant role in the acetolysis or trifluoroacetolysis of isobutyl tosylate.

26. Solvolysis of 1-OTf-1-14C in unbuffered HOAc resulted in about 32% rearrangement of the 14C-label from C-1 to C-2, a value that is almost the same as that observed for the analogous acetolysis of 1-OTs-1-14C.

27. The acetolysis-inversion reaction has been carried out with 2,3;5,6-di-O-isopropylidene-D-gulofuranose, 2,3;6,7-di-O-isopropylidene-D-glycero-D-gulo-heptose, 2,3-O-isopropylidene-D-ribose, D-ribose, and D-mannose using chromatography for isolation of the deacetylated epimeric products.

28. Acetolysis of 1,6-anhydro-2,3,4-tri-O-benzyl-β-D-galactopyranose (3) followed by de-O-acetylation and p-nitrobenzoylation gave 2,3,4-tri-O-benzyl-1,6-di-O-p-nitrobenzoyl-β-D-galactopyranose (4) which was converted into 2,3,4-tri-O-benzyl-6-O-p-nitrobenzoyl-α-D-galactopyranosyl bromide (5).

29. These results are discussed in conjunction with earlier data from the acetolysis of doubly labeled 1,2-dianisyl-2-p-[14C]methoxyphenyl[2-13C]vinyl bromide (1-Br-2-13C-2-methoxy-14C) which gave, depending on experimental conditions, either equal or unequal values for the % rearrangement in the chain and in the ring label.

30. For nine of these donors, the kinetic data were analyzed to obtain the rate constant, kc, for acetolysis of the 1:1 donor–substrate complex, and the 1:1 donor–substrate association constant, K. Two measures of catalytic effectiveness, log kc and log kcK correlate well with the highest occupied molecular orbital energy of the donor, E(HOMO), calculated by the Hückel molecular orbital (HMO) method.