ABSTRACT
An inexpensive iron-catalyzed alkoxyl radical-induced C-C bond cleavage/gem-difluoroalkylation cascade is presented. Regulated by the structure of alkoxyl radical precursors, fluorinated distal diketones were synthesized through a ring-opening strategy and difluoroalkylated medium-sized lactones and macrolactones were constructed via a ring-expansion strategy. Both protocols proceeded under mild and redox neutral conditions with a broad substrate scope and good functional group compatibility.
Subject(s)
Iron , Ketones , Lactones , CatalysisABSTRACT
A rapid method for the determination of trace chrysene in environmental water by solid-phase microextraction (SPME) coupled with high performmnce liquid chromatography (HPLC) was developed. The experimental conditions of SPME, such as extraction time, extraction temperature, effect of ion strength, desorption time, desorption solution, desorption mode and the analytical conditions of HPLC were optimized. The optimal conditions were room temperature, 1,100 r/min of stirring rate, 30 min of extraction time, 3 min of desorption time, and methanol as the desorption solution. Methanol was used as the mobile phase on a C18 reversed phase chromatographic column. The flow rate was 1 mL/min. The detection wavelength was 266 nm on a UV-Vis detector. The linear range was from 0.013 microgram/L to 3.0 micrograms/L, the detection limit was 2.7 ng/L, and the relative standard deviation (RSD) was 5.6%. The method was used for the determination of trace chrysene in tap water, mineral water, rain water and river water. The recoveries were from 103.2% to 119.3%, the RSDs were from 4.8% to 10.2%. The method is fast, convenient, sensitive, solvent-free, and suitable for the determination of trace chrysene in environmental water.
