DPPH radical scavenging reactions of protocatechuic acid and its methyl ester were investigated in various solvents. In alcoholic solvents, methyl protocatechuate rapidly scavenged more than four equivalents of the radical, whereas approximately two equivalents were consumed in aprotic solvents. Methyl, ethyl, butyl, isopropyl, and tert-butyl protocatechuates were examined for their DPPH radica...

The title compound, C21H42O5Si2, was synthesized from (3R,4S,5R)-methyl 3,5-bis-[(tert-butyl-dimethyl-sil-yl)-oxy]-4-hy-droxy-cyclo-hex-1-ene-carboxyl-ate by an esterification reaction. The cyclo-hexene ring adopts a half-chair conformation. In the crystal, mol-ecules are linked via C-H⋯O hydrogen bonds, forming helical chains propagating along [010].

Efficient conversion of ketones into kinetic enol phosphates under mild and accessible conditions has been realised using the developed methods with di-tert-butylmagnesium and bismesitylmagnesium. Optimisation of the quench protocol resulted in high yields of enol phosphates from a range of cyclohexanones and aryl methyl ketones, with tolerance of a range of additional functional units.

In the structure of the title compound, C(24)H(23)Br, the configuration about the double bond is E. The dihedral angles between the tert-butyl-substituted benzene ring and the unsubstituted and Br-substituted rings are 57.1 (2) and 78.2 (2)°, respectively. The methyl groups are disordered over two positions; the site occupancy factors are ca 0.8 and 0.2.

two pure bacterial strains capable of rapid degrading methyl tert–butyl ether (mtbe) were isolated from an industrial wastewater treatment plant, identified and characterized. these strains are able to grow on mtbe as the sole carbon and energy sources and completely mineralize it to the biomass and carbon dioxide. the strains were identified as bacillus cereus and klebsiella terrigena. both st...

In the title mol-ecule, C(20)H(18)O(4), the three methyl groups of the tert-butyl substituent show rotational disorder. Each methyl group is split over three positions, with refined site-occupation factors of 0.711 (4), 0.146 (3) and 0.144 (4). The benzene ring of the benzoate group is oriented at a dihedral angle of 60.70 (7)° with respect to the planar chromene ring [maximum deviation = 0.046...

In the title compound, C(27)H(26)N(2)O(6), the imidazolidine ring adopts an envelope conformation. The methyl group on the imidazolidine ring is disordered over two positions with occupancies of 0.517 (11) and 0.483 (11), and the 3,4-methyl-enedioxy-phenyl at the 3-position of imidazolidine ring is also disordered over two positions with occupancies of 0.60 (2) and 0.40 (2).

Atom transfer radical coupling (ATRC), performed with or without traps, has allowed for high extents of (Xc) a variety brominated polymers, yet structurally different polymeric chain ends require unique reagents and reaction conditions. Inspired by similar study that focused on universal conditions the controlled polymerization monomers using atom (ATRP), this work focuses developing single set...

In response to the widespread contamination caused by MTBE-blended reformulated gasoline (RFG), legislative initiatives in several states and at the federal level have phased out, or are trying to phase out, the use of MTBE as a gasoline oxygenate. Ethanol is currently the most likely gasoline oxygenate alternative to MTBE. This potential for increased use of ethanol has been most widely acknow...

The environmental contamination and fate of benzotriazole UV stabilizers (BZTs) have received increasing attention due to their large production volume and wide usage in various consumer and industrial products. In the present work, 60 municipal sewage sludge samples from wastewater treatment plants (WWTPs) in 33 cities in China were collected to investigate the occurrence and distribution of 9...