Synthesis of ortho-Substituted Arylacetic Esters and Related Compounds by Means of Sommelet-Hauser Rearrangement of Sulfur Ylides.
作者:Hiroyuki ISHIBASHI、Takashi TABATA、Tetsuya KOBAYASHI、Iwao TAKAMURO、Masazumi IKEDA
DOI:10.1248/cpb.39.2878
日期:——
The rearrangement of a series of dimethylsulfonium α-substituted benzylides, e.g., 8, in ethanol has been examined. The ylides 8a, b generated in situ by treatment of the sulfonium salts 7a, b with 1, 8-diazabicyclo[5.4.0]undec-7-ene (DBU) in ethanol at room temperature, afforded the o-(methylthiomethyl)phenylacetic esters 10a, b as a result of the Sommelet-Hauser rearrangement of the tautomeric ylides 9a, b. By contrast, the ylide 14 possessing a furan ring was stable at room temperature, but, on heating in ethanol, gave the rearranged product 15. The ylide 22 stabilized by an acetyl group provided three rearranged products, 23, 24, and 25, in boiling ethanol. Treatment of the sulfonium salts 30a, b with DBU at room temperature afforded the corresponding rearranged products 31a, b. The sulfonium salt 34a prepared from 33a, on treatment with sodium ethoxide, gave the rearranged product 36a, which was then S-methylated and treated with DBU to give the 1, 2, 3-trisubstituted benzene 37a. This method was applied to the synthesis of the fenoprofen analog 39 from 39 from 33b, c.
在乙醇中对一系列二甲基磺鎓α取代苄亚胺(例如8)的重排进行了研究。通过在室温下将磺鎓盐7a、b与1, 8-二氮杂双环[5.4.0]十一烯(DBU)处理,原位生成的亚胺8a、b经过Sommelet-Hauser重排反应得到了o-(甲硫基甲基)苯乙酸酯10a、b。相比之下,含有呋喃环的亚胺14在室温下稳定,但在乙醇中加热后产生了重排产物15。由乙酰基稳定的亚胺22在沸腾的乙醇中提供了三个重排产物23、24和25。将磺鎓盐30a、b与DBU在室温下处理,得到了相应的重排产物31a、b。由33a制备的磺鎓盐34a与乙醇钠反应后生成了重排产物36a,随后对其进行了S-甲基化处理,并用DBU处理,得到1,2,3-三取代苯37a。该方法被应用于从33b、c合成芬普芬类药物39。