The oxidativecleavage of indoles (Witkop oxidation) involving the use of H2O2 or urea hydrogenperoxide in combination with a polar solvent has been described. Among these solvents, 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) stands out as the one affording the corresponding 2-ketoacetanilides generally in higher yields The protocol described has also enabled the oxidation of different pyrroles and furans
已经描述了涉及使用 H 2 O 2或过氧化氢尿素与极性溶剂的吲哚的氧化裂解(Witkop 氧化)。在这些溶剂中,1,1,1,3,3,3-六氟异丙醇 (HFIP) 脱颖而出,通常以更高的产率提供相应的 2-酮乙酰苯胺。所描述的协议还能够氧化不同的吡咯和呋喃衍生物。此外,该程序是大规模实施的,从反应混合物中蒸馏出 HFIP 并重复使用(最多 4 个循环),而不会显着损害反应结果,这说明了其可持续性和适用性。
An Efficient Synthesis of 4-Oxoalkenoic Acids from 2-Alkylfurans
作者:Robert G. Salomon、Suresh Palani Annangudi、Mingjiang Sun
DOI:10.1055/s-2005-869833
日期:——
An efficient synthesis of 4-oxo-2-alkenoic acids is achieved by the reaction of 2-alkylfurans with sodium chlorite in acidic aqueous solution. The method is applicable to the total synthesis of biologically active phospholipids containing this functional array. The oxidation procedure also converts 2,5-dialkyl furans to α,β-unsaturated-y-diketones in good yields.
作者:Brian M. Adger、Collette Barrett、Joseph Brennan、M. Anthony McKervey、R. W. Murray
DOI:10.1039/c39910001553
日期:——
Dimethyldioxirane reacts rapidly at room temperature in acetone with a variety of furans, furnishing in high yield products of oxidative ring opening and, with 2-furanmethanol, 2H-pyran-3(6H)-one via subsequent ring closure.
Photooxygenation of differently functionalized furans is investigated in aqueous solutions and in ionic liquids [emim]Br and [bmim]BF4. The reaction is generally selective and the final products derive from rearrangement of the intermediate endoperoxides, depending mainly on the polarity and/or nucleophilic nature of the solvent.