| Summary: | 博士 === 高雄醫學大學 === 藥學研究所 === 84 === The conjugate addition of(5S)-5-phenyl-N-methacryloyl oxazolidin-2-one(E2-4) with thioacetic acid in the presence of TiCl4 gave the addition adducts in 87% yield and 14% de. When this reaction was carried out in the absence of TiCl4, good diastereoselectivity(94% de) was observed. A similar result was obtained by employing thiobenzoic acid as a nucleophile. The reaction of E2-4 with other thiols, such as thiophenol, 4-methoxythiophenol, 2-methoxythiophenol, methyl 3-mercatopropionate, methyl thioglycolate and methyl thiosalicylate, required TiCl4 to give the addition adducts in good chemical yields and the diastereoselectivities are ranbing from 50 to 82% de. 2-Aminothiophenol was also employed in this study to give the addition adducts in 60% yield and 70% de when the reaction was carried out in the absence of TiCl4. In the presence of TiCl4, this reaction provided the addition adducts as racemic mixture in 28% yield along with l,5-benzothiazepin-4-one in 56% yield. This observation has stimulated us to investigate the TiCl4-catalyzed aminolysis ofN-acyloxazolidinone and kinetic resolution of arylamine.
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