fumarates and methyl-acrylate

Chairs and sofas imported from China to Europe were shown to contain dimethyl fumarate (DMF), a sensitizing, volatile chemical. Many of the sensitized patients also had positive patch test reactions to acrylates.. To analyse the occurrence and strength of DMF sensitization and the appearance of concomitant reactions.. Patch testing with DMF in concentrations of 0.1-0.00001% was carried out in 37 patients. Diethyl fumarate (DEF), diethyl maleate (DEM), dimethyl maleate (DMM), ethyl acrylate (EA), methyl acrylate (MA), and methyl methacrylate (MMA) were also tested with a dilution series at equimolar concentrations.. The lowest concentration of DMF eliciting a reaction varied between 0.0001% and 0.1% and all but four patients reacted concurrently to DEF. DEM elicited positive patch test reactions in 21/37 patients and DMM reactions were seen in all 9 patients tested. EA elicited positive reactions in 13/37 patients and a positive MA reaction was seen in 7/37 patients, 2 of whom also reacted to MMA.. The strength of the sensitization to DMF showed variation and concurrent reactions were common. Concurrent reactions to (meth)acrylates were seen in patients, who reacted to lower (0.001% or less) DMF concentration probably elicited by cross-reactivity.

Topics: Acrylates; Adult; China; Dermatitis, Allergic Contact; Dimethyl Fumarate; Female; Finland; Fumarates; Humans; Interior Design and Furnishings; Male; Maleates; Methylmethacrylate; Middle Aged; Patch Tests; United Kingdom

The cationic oxazaborolidine-catalyzed Diels-Alder reactions of butadiene and a series of five dienophiles have been studied using density functional theory (B3LYP/6-31G(d)). In each case, the computational results successfully reproduce the experimentally observed sense of stereoinduction and enantiomeric ratio. The computed structures of the lowest energy Lewis acid-carbonyl complexes and Lewis acid-transition state complexes are closely related to the models for stereoselection proposed by Corey and co-workers.

Topics: Acrolein; Acrylates; Benzoquinones; Boron Compounds; Bridged Bicyclo Compounds, Heterocyclic; Butadienes; Computer Simulation; Dimethyl Fumarate; Fumarates; Models, Molecular; Molecular Conformation; Stereoisomerism; Substrate Specificity