The first NHC-catalyzed functionalization of carboxylic anhydrides is described. In this reaction, the β carbon behaves as a nucleophilic carbon and undergoes asymmetric reactions with electrophiles. Anhydrides with challenging β-alkyl substituents work effectively.

Risk factors for bronchial hyperresponsiveness have previously been established in the general community. In settings where occupational asthma is a risk, it has not been established whether occupational sensitization or measures of exposure are important. Bronchial responsiveness to histamine was measured in a cohort of 506 workers exposed to acid anhydrides. Skin-prick tests were performed wi...

The present study describes an economic and scalable approach to aqueous mesophases from bola-amphiphiles (BA) obtained via nucleophilic addition of dimer fatty acid based α,ω-polyesterdiols (PES) on cyclic acid anhydrides and conversion of the carboxylic end groups into ammonium salts. Novel bola-amphiphilic head groups are introduced using alkenyl succinic anhydrides (ASA). The additional ter...

During modification of protein amino groups with carboxylic acid anhydrides, these reagents cause a fall in pH, which can be prevented by addition of base. Although unmodified nucleosomal particles are not affected by the local transient changes in pH induced by the base (NaOH) added to prevent a fall in pH during modification, the nucleosomal particles modified by acetic anhydride are dissocia...

Z. Naturforsch. 51 b, 409-416 (1996); eingegangen am 28. Juni 1995 Reduction, Narthigenine, Butyrolactones, Butyrolactams, Tetramic Acids A series of potentially cytotoxic a,/?-unsaturated 7 -hydroxy-butyrolactones, -lactams and -thiolactones has been synthesized via regioselective hydride reduction of the appropriate maleic acid anhydrides, imides and thioanhydrides. By this means a straightfo...

Coenzyme A esters of all-trans- and 13-cis-retinoic acid were synthesized for use in studying vitamin A metabolism. The esters were obtained by two different synthetic methods starting from retinoic acids, which were converted to activated succinimidyl esters or anhydrides. These in turn were coupled with coenzyme A to form their respective thioesters. The retinoyl coenzyme A esters were purifi...