298-18-0Relevant articles and documents
Chiroptical properties of 2,2’-bioxirane
Daugey,De Rycke,Brotin,Buffeteau
, p. 342 - 350 (2018/01/15)
The two enantiomers of 2,2′-bioxirane were synthesized, and their chiroptical properties were thoroughly investigated in various solvents by polarimetry, vibrational circular dichroism (VCD), and Raman optical activity (ROA). Density functional theory (DFT) calculations at the B3LYP/aug-cc-pVTZ level revealed the presence of three conformers (G+, G?, and cis) with Gibbs populations of 51, 44, and 5% for the isolated molecule, respectively. The population ratios of the two main conformers were modified for solvents exhibiting higher dielectric constants (G? form decreases whereas G+ form increases). The behavior of the specific optical rotation values with the different solvents was correctly reproduced by time-dependent DFT calculations using the polarizable continuum model (PCM), except for the benzene for which explicit solvent model should be necessary. Finally, VCD and ROA spectra were perfectly reproduced by the DFT/PCM calculations for the Boltzmann-averaged G+ and G? conformers.
METHOD FOR REPROCESSING MIXTURES CONTAINING BIS-EPOXIDE
-
Page/Page column 11-13, (2008/06/13)
The invention relates to a method for reprocessing mixtures containing (a) one or several bis-epoxides of general formula (I), wherein R1 and R2 are identical or different and are selected among hydrogen and C1-C3 alkyl, (b) one or several organic solvents, (c) water, and (d) other optional compounds. The inventive method is characterized in that the mixture is subjected to an at least two-stage distillation process, at least one bis-epoxide (a) being converted into the gas phase in at least one stage.
METHOD FOR THE PRODUCTION OF BISEPOXIDES AND DITHIOLS
-
Page/Page column 16; 17, (2008/06/13)
The invention relates to a method for the production of bisepoxides, characterised in that a conjugated diene of formula (I) is reacted with at least one peroxide with the application of up to 4 equivalents of peroxide per C-C double bond, where R1 is selected from hydrogen and C1-C12 alkyl, unsubstituted or substituted with one or several SH or OH groups, in the presence of a catalyst, obtained by the bringing into contact of at least one manganese compound, selected from A2MnX4, AMnX3, MnY, MnX2 and MnX3 with at least one ligand L, of general formula (II), whereby the variables have the following definitions: X may be the same or different and is selected from monovalent anions, Y is a divalent anion, A is selected from alkali metals and optionally alkylated ammonium, R2 may be different or preferably the same and selected from C1-C20 alkyl and at least one co-ligand, derived from monocarboxylic acids, di- or poly-carboxylic acids or diamines.