Towards the total synthesis of anthraquinone antifungal agents Sch 47554 and Sch 47555

The total synthesis of Sch 47554 (1) is the focus of this project, with the intention of using two aryne-furan cycloaddition reactions to efficiently build the anthraquinone core of the molecule. The first is intermolecular with furan, which is then elaborated with a C-aryl glycosidation reaction. T...

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Bibliographic Details
Main Author: Espensen, George Max
Other Authors: Barrett, Anthony
Published: Imperial College London 2011
Subjects:
540
Online Access:http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.544268
Description
Summary:The total synthesis of Sch 47554 (1) is the focus of this project, with the intention of using two aryne-furan cycloaddition reactions to efficiently build the anthraquinone core of the molecule. The first is intermolecular with furan, which is then elaborated with a C-aryl glycosidation reaction. The second is intramolecular between 5 and 6 where the two fragments are linked by a disposable tether connected through the oxygen functionalities, as demonstrated in 2. This ensures the correct angularly-fused regiochemistry of the aryne-furan cycloaddition. [Molecular structure diagrams appear here. To view, please open pdf attachment]. To this end suitable precursors have been examined. After several unsuccessful attempts at making various suitably-functionalised precursors, double aryne precursor 8 was synthesised and converted into naphthol 10. This was successfully glycosylated, but this substrate is less flexible later in the synthesis than another substrate developed, 9. This was converted into naphthol 10 and the glycosidation is currently being optimised. Elsewhere in the group furan 6 has been synthesised. These systems are appropriate for completing the synthesis of 1. [Molecular structure diagrams appear here. To view, please open pdf attachment].