Liebigs Annalen der Chemie 2014-05-01

Synthetic Studies Towards the Core Structure of Nakadomarin A by a Thioamide-Based Strategy.

JaiK Chavda, PanayiotisA Procopiou, PeterN Horton, SimonJ Coles, MichaelJ Porter

Index: European J. Org. Chem. 2014(1) , 129-39, (2014)

Full Text: HTML

Abstract

The tricyclic BCD substructure of the marine natural product nakadomarin A has been synthesised. The strategy utilised a key carbon-carbon bond-forming reaction between a furan and an N-acyliminium ion derived from a secondary thiolactam. In addition, a novel three-component coupling reaction between a thioamide, an allylic bromide and an isocyanate, leading to the establishment of two new stereogenic centres, is reported. Two key steps in a projected total synthesis of nakadomarin A have been realised by using the unique chemistry of thioamides. Formation of the carbocyclic B ring can be effected by nucleophilic attack of a furan on a thiolactam-derived iminium ion, and the key quaternary centre can be established by a novel three-component coupling reaction.