Abstract Aliphatic esters are essential constituents of biologically active compounds and versatile chemical intermediates for the synthesis drugs. However, their preparation from readily available olefins remains challenging. Here, we report a strategy to access aliphatic through photocatalyzed alkoxycarbonylation reaction. Alkyloxalyl chlorides, generated in situ corresponding alcohols oxalyl...

Welschriesling is a variety common to Central and Eastern European wine-producing countries; however, its aromatic composition remains poorly understood. Our study aims determine the volatile profile of by analysing varietal thiols, esters, higher alcohols monoterpene in commercial wines. In addition, selection yeast starters lactic acid bacteria (LAB) was used modulate wine composition. Both L...

The formation of an acyl-enzyme intermediate in the chymotrypsin-catalyzed reactions of esters (l-3) is widely held to be established, although some data do not quantitatively fit the theory (4, 5) and there is some dissent from this view. One of the simplest and most convincing ways of demonstrating the formation of an acyl-enzyme intermediate is to show that the chymotrypsin-catalyzed solvoly...

The oxygen that a wine receives during the winemaking process defines its properties. aim of this work was to evaluate consumption capacity wines and influence on modification their composition. This preliminary evaluated changes after 3 months in chemical composition twenty-seven Spanish commercial red, white rosé air saturation oxidation at 35 °C for 7 days. All studied were high consumers, w...

Botanisches Institut der Universität zu Köln, Gyrhofstraße 15, D-5000 Köln 41 Z. Naturforsch. 40c, 599—605 (1985); received May 6, 1985 Epicuticular Waxes, Alpine Plants, Ecophysiology, Relation to Altitude, Ultrastructure Epicuticular waxes were extracted and analysed from leaves of 7 different high alpine plant species, with 3 species harvested at different altitudes: Salix herbacea (1950 m, ...

Ageing on lees can be a good technique to enhance the quality of red sparkling base wines. Ultrasound treatment lees, prior addition wine, improve releasing their components into wine. This study carries out four month ageing wine by sonicated at different amplitude levels: 30%, 60% and 90% for 10 min. The ultrasound-treated improved with greater impact higher applied ultrasound. Sonicated an e...

The seasonal development of adaxial Prunus laurocerasus leaf surfaces was studied using newly developed methods for the mechanical removal of epicuticular waxes. During epidermal cell expansion, more than 50 microg leaf(-1) of alkyl acetates accumulated within 10 d, forming an epicuticular wax film approximately 30 nm thick. Then, alcohols dominated for 18 d of leaf development, before alkanes ...

Two different methodologies for the synthesis of monotelechelic poly(oxa)norbornenes prepared by living ring-opening metathesis polymerization (ROMP) are presented. The first method, termed direct end-capping, is carried out by adding an internal cis-olefin terminating agent (TA) to the reaction mixture immediately after the completion of the living ROMP reaction. The second method relies on cr...