A Nitrone Based Route to Polyhydroxylated Lactams and Piperidines: An Expeditious Synthesis of rac-Fagomine
作者:Fabio Degiorgis、Marco Lombardo、Claudio Trombini
DOI:10.1055/s-1997-1345
日期:1997.11
The synthetic versatility of tetrahydrofuro[2,3-d]isoxazol-5(2H)-ones, obtained from TMSOTf-promoted addition of 2-trimethyl-silyloxyfuran to nitrones, is demonstrated in a two-step reductive sequence to give the title compounds. The cycloadducts obtained from a glycolaldehyde derived nitrone are first reduced with DIBAH, then hydrogenolyzed in the presence of Pd(OH)2 to give polyhydroxylated piperidines, including rac-fagomine. Direct hydrogenolysis of the same cycloadducts gives an easy entry to polyhydroxylated lactams.
四氢呋喃并[2,3-d]异恶唑-5(2H)-酮是由 2-三甲基-硅氧基呋喃在 TMSOTf 的促进下与硝基酮加成得到的,通过两步还原顺序得到标题化合物,证明了四氢呋喃并[2,3-d]异恶唑-5(2H)-酮的合成多功能性。首先用 DIBAH 还原从乙醛衍生的腈酮得到的环加载产物,然后在 Pd(OH)2 存在下进行氢解,得到多羟基哌啶类化合物,包括 rac-fagomine。直接氢解相同的环加载产物,很容易得到多羟基内酰胺。