Search results for " alcohol"

STUDIEN ZUM VORGANG DER WASSERSTOFFÜBERTRAGUNG 611

1982

Abstract In arylsulfonyl halides, the half-wave potentials of the corresponding chlorides and fluorides differ by more than 1000 mV, the fluoride being more negative; the influence of para-substituents is small for the chlorides, large for the fluorides. In agreement with the half-wave potentials, arylsulfonyl chlorides are considerably more reactive chemically than the corresponding fluorides. The O-selectivity found for P(O)F compounds is not observed in arylsulfonyl fluorides. Studies of competitive ester formation using primary and secondary alcohols and various arylsulfonyl chlorides yielded no clear analogy to the half-wave potentials. The primary alcohol is always sulfonated in prefe…

Polyfurfuryl alcohol composite as adsorbent of polychlorinated biphenyls and pyrethroid insecticides

2007

Abstract Composites from furfuryl alcohol and silica gel were prepared in dichloromethane using trifluoroacetic acid as catalyst and characterized by means of thermogravimetric analysis, transmission electron microscopy and nitrogen adsorption–desorption isotherms. The polymer content in the composites ranged between 19.5% and 32.9%. The capability to adsorb polychlorinated biphenyls and pyrethroid insecticides was tested for composite samples containing different percentages of polymer. Pyrethroids are retained almost totally by composites containing around 24–33% of polymer, while recovery of PCBs close to 80% is obtained with all the composites. No selectivity between compounds of the sa…

Metal-organic frameworks-based catalysts for biomass valorization

2020

Abstract The objective of this chapter is to review the most promising metal-organic framework (MOF) catalysts in biomass valorization processes in the bulk and fine chemical industries. Either bulk metal-organic frameworks, encapsulated catalytic species in MOFs, or MOF-derived catalysts are revised in terms of activity, selectivity, and stability for biomass valorization applications. The work revised here is focused on the transformation of lignocellulose biomass through purely chemical pathways. In the first part of the chapter, the few studies of cellulose hydrolysis into monosaccharides reported are commented, since this crucial first step in the valorization of hemicellulose is expec…

Evaluación de Consecuencias derivadas del Consumo de Alcohol (ECCA)

2019

Escala de evaluación de consecuencias derivadas derivadas del consumo de alcohol

1,1-Diphenyl-4-(thiophen-2-yl)but-3-yn-1-ol

2018

The asymmetric unit of the title homopropargyl alcohol, C20H16OS, contains two independent molecules comprising a hydroxy group, a 3-(2-thiophenyl)- propargylic moiety and two aromatic rings linked to a central carbon atom. The two unique molecules are linked into a dimer by an O—HO hydrogen bond. In one molecule, the thiophene ring is disordered over two orientations rotated by 180 with a refined occupancy ratio of 0.575 (4):0.425 (4). The crystal structure is stabilized by O—H and C—H hydrogen-bond interactions. The crystal studied was a two-component non-merohedral twin, the refined ratio of the twin components being 0.575 (4):0.425 (4). UCR::Vicerrectoría de Docencia::Ciencias Básicas::…

Relationship between dysfunctional eating patterns and binge drinking in young people and associated risk factors

2022

La joventut (compresa entre els 18 i 30 anys) es considera un període de vulnerabilitat, en què és freqüent observar trastorns alimentaris, consum de drogues i una major tendència a buscar noves sensacions i comportaments de risc, entre moltes altres conductes. En concret, hi ha dos comportaments molt prevalents en els joves i s'associen amb conseqüències de salut molt negatives: el consum de menjar ultraprocessat i el consum d'alcohol. Tot i això, el problema no rau només en el tipus de consum (és a dir, beure alcohol o menjar menjar ràpid), sinó també en com es consumeix l'alcohol o el menjar. L'afartament es caracteritza per la ingesta de grans quantitats de menjar (afartament de menjar)…

Recent developments and applications of the chiral Brønsted acid catalyzed allylboration of carbonyl compounds

2018

The 50-year-old allylboration reaction has seen dramatic developments since the dawn of the new century after the first catalytic asymmetric versions came into play. In the past decade alone, several methodologies capable of achieving the desired homoallylic alcohols in over 90% ee have been developed. This review focuses on the chiral Brønsted acid catalyzed allylboration reaction, covering everything from the very first examples and precedents to modern day variations and applications.1 Introduction2 Early Developments3 Synthetic Applications4 Variants5 Computational Contribution6 Conclusions

Lipase-catalysed preparation of acyl derivatives of the germacranolide sesquiterpenoid cnicin

2009

Several acyl derivatives of cnicin were obtained through lipase-catalysed acylation and alcoholysis reactions. In most reactions lipases showed a regioselective behaviour affording only one product. Longer chain acyl derivatives were prepared at lower temperature than the used in lipase-catalysed reactions, to preclude side products formation. The enzymatic approach let to prepare a family of novel acetyl and fatty acid derivatives of cnicin which are not obtainable following traditional organic synthetic procedures.

Neuropsychiatric aspects of fetal alcohol syndrome in children.

2011

Involvement of an Alkane Hydroxylase System of Gordonia sp. Strain SoCg in Degradation of Solid n-Alkanes▿

2010

ABSTRACT Enzymes involved in oxidation of long-chain n -alkanes are still not well known, especially those in Gram-positive bacteria. This work describes the alkane degradation system of the n -alkane degrader actinobacterium Gordonia sp. strain SoCg, which is able to grow on n -alkanes from dodecane (C 12 ) to hexatriacontane (C 36 ) as the sole C source. SoCg harbors in its chromosome a single alk locus carrying six open reading frames (ORFs), which shows 78 to 79% identity with the alkane hydroxylase (AH)-encoding systems of other alkane-degrading actinobacteria. Quantitative reverse transcription-PCR showed that the genes encoding AlkB (alkane 1-monooxygenase), RubA3 (rubredoxin), RubA4…