A carbohydrate approach to polyol fragments of amphotericin and the trienomycin- and mycotrienin antibiotics
作者:Alois Fürstner、Judith Baumgartner
DOI:10.1016/s0040-4020(01)96261-1
日期:1993.9
central precursor for the synthesis of both the C1C6 as well as C7C13 unit of the polyhydroxylated chain of amphoteronolide B. Combining these two segments 45 and 51 by ketophosphonate/aldehyde coupling afforded enone 54 which is synthetically equivalent to an intermediate of a former total synthesis of this macrolide. Thus, a convergent synthesis of the C1C13 fragment of amphotericin B based upon
水解不稳定的ω-氯-ω-苯基硫代糖苷,得自相应的ω-苯基硫代糖苷,经NCS在CCl 4中处理后,很容易在无水溶剂中用Zn / Ag-石墨脱烷氧基卤化,从而提供对映体纯的合成子,该合成子在一端具有醛功能,并且开环产物另一端的乙烯基硫醚基。事实证明,这种片段化技术是通用的,用于合成显示所有Trienomycin-,mycotrienin和Ansatrienin大环内酯类抗生素共有的C9C14片段取代模式的构件。Zn / Ag-石墨还用于还原性地将D-葡萄糖容易获得的6-脱氧-6-碘吡喃糖苷37开环成烯38,它是合成两性戊内酯B多羟基化链的C1C6和C7C13单元的主要前体。通过酮膦酸酯/醛偶联将这两个链段45和51结合,得到烯酮54,该烯酮在合成上等同于该大环内酯以前的全合成中间体。因此,基于金属-石墨促进的碳水化合物开环,在关键步骤中结合构型的正式反转,实现了基于该目标分子隐藏的C 2