An efficient and convenient strategy has been successfully developed for the preparation of novel hydroxylated alkaloid derivatives (also called fused multicyclic iminosugars) from p-toluenesulfonylated sugars through a Pictet-Spengler-type mechanism. This method is highly stereoselective, does not require metal catalysts, and capable of conducting gram level reactions (with a 53% yield). Some of such iminosugars had an intermediate antiproliferative effect on HCT116 tumor cells.
Keywords: Pictet–Spengler reaction; antitumor activity; fused multicyclic iminosugars; hydroxylated alkaloids.