| In the current study the total synthesis of the marine natural products spermatinamine, an isoprenylcysteine carboxyl methyltransferase (Icmt) inhibitor, and Aspergillusol A, an alpha-glucosidase inhibitor were accomplished by using a convergent appraoch. Besides these, the first total synthesis of 2'-methoxy-3'-prenyl-licodione, an Icmt inhibitor, was also attempted. All the three natural products exhibited potent biological activities. The Icmt inhibitors are potential anticancer drug targets, while Aspergillusol A, holds promise as antidiabetic drug. The key step of amidation in spermatinamine synthesis was achieved by transforming the hydroxamic acid to acid chloride followed by condensing it with the appropriate amine, with an overall yield of 52%. Aspergillusol A was synthesized by estrification of intermediates, erythritol and appropriate hydroxamic acid, in the presence of DCC with a high overall yield (60%). Key feature of synthesis of 2'-methoxy-3'-prenyl-licodione is crossed-claisen condensation of the two key intermediates with employment of various protective groups and bases. A better synthetic approach involving condensation of coumarin derivative and Grignard partner was proposed. |
