A Sommelet–Hauserrearrangement of sulfonium ylides of 4H-pyran-4-ones, furan, and thiophenes are discussed. The sulfonium halides which were prepared from excess dimethyl sulfide with corresponding halides were treated with NaH or NaOR in a polar solvent to give moderate to good yields of rearranged products.
讨论了 4H-吡喃 4-酮、呋喃和噻吩的锍叶立德的 Sommelet-Hauser 重排。由过量二甲硫与相应卤化物制备的锍卤化物在极性溶剂中用 NaH 或 NaOR 处理,得到中等至良好收率的重排产物。
Synthesis and characterization of new crown-type compounds with 4-pyrone Units
one and two 4-pyrone units. The reaction of compound 3 with 1,5-bis(2-hydroxyphenoxy)-3-oxapentane or catechol gave the desired molecules 8 and 9 in 65% and 25% yields, respectively. Compound 3 resulted from 1 by Wohl-Ziegler bromination in small amounts and could be separated from five bromination by-products by column chromatography. For example, 8 binds K+ and a pyrylium salt 11 (single crystal X-ray