求助琼斯试剂的制备方法？ 太巧了，昨天刚刚看了一篇文献关于jones oxidation jones oxidation of 1-o-tolyl-propan-2-ol to 1-o-tolyl-propan-2-one chemicals used chromium trioxide (lancaster) 1-o-tolyl-propan-2-ol acetone (gpr) conc h2so4 (bdh) water procedure chromium trioxide (12.8 g, 0.128 mol) was dissolved in 18 ml water (142 ml/molcro3)in a beaker. the resulting solution was cooled to 0oc whereupon 11 ml conc h2so4 (87 ml/mol cro3) was added dropwise. the solution was diluted with 36 ml water (285 ml/mol cr03) and cooled to 0oc. a solution of the alcohol (19.2 g, 0.128 mol) in acetone (80 ml) (600ml/mol cro3) was cooled to 0oc and the jones reagent added slowly, maintaining a temperature 20oc. stirring was continued for 3 h at 0oc. sodium bisulfite was added in small portions until the brown colour of the chromic acid had disappeared from the upper layer. the top layer was decanted and the lower layer extracted with ether (2 x 200 ml). the extracts were combined and washed with nacl solution, dried over mgso4, filtered and concentrated in vacuo. the resulting brown oil was purified by chromatography on silica gel with petrol:ethyl acetate (10:1) as the eluent yielding the title compound as a yellow oil (14.2g, 75%). author's comments although this reaction is very commonly used in synthesis, i found it difficult to find exact conditions when searching. the literature assumes that everyone knows how to make the reagent! although i have only carried out this reaction once, i found it high yielding and easy to follow. data 1h nmr (300 mhz, cdcl3)2.15 (3h, s), 2.26 (3h, s), 3.72 (2h, s), 7.13-7.20 (4h, m). -------------------------------------------------------------------------------- lead reference shibuya, masayuki; tetrahedron lett.; 1983; 1175-1178 other references org synth coll. 5, 1973, 866查看更多
第1天
关注盖德视界
添加小助手
