Regioselective Lithiation and Functionalization of 3-(Benzyloxy)isothiazole: Application to the Synthesis of Thioibotenic Acid
作者:Lennart Bunch、Povl Krogsgaard-Larsen、Ulf Madsen
DOI:10.1021/jo0162134
日期:2002.4.1
Direct functionalization of the 3-oxygenated isothiazole heteroaromatic parental system has not yet been reported in the literature. Here, we report the first regioselective lithiation of the 5-position of 3-(benzyloxy)isothiazole (4) using LDA in diethyl ether. The versatility of the methodology was explored by quenching with a variety of electrophiles to give the desired products 7a,b,d-g in 54-68%
3-氧代异噻唑杂芳族亲本系统的直接官能化尚未在文献中报道。在这里,我们报道了在乙醚中使用LDA对3-(苄氧基)异噻唑(4)的5位的第一个区域选择性锂化。通过用各种亲电试剂淬灭来探索该方法的多功能性,以54-68%的产率得到所需产物7a,b,dg。仅针对7c合成的苯甲酰化是不成功的。此外,还进行了高度收敛的硫代苯甲酸(1)的合成,后者是神经毒性天然产物ibotenic酸的硫类似物。