The construction of the central 6-7-6 core ring system that exists in sugar-fused erinacines by an efficient samarium-mediated radial cyclization was investigated. It was observed that the samarium-mediated 7-endo-trig radial cyclization afforded excellent stereocontrol of the four contiguous asymmetric centers present in the 6-7-6 tricyclic cores of the erinacines E, F and G. The erinacines were isolated from myceria of the fungus Hericium erinaceum as potent simulators of nerve growth factor (NGF) synthesis. The resulting samarium enolate was protonated stereoselectively to afford thermodynamically more stable as a single isomer. The studies constituted a firm basis for synthesis of the sugar-fused erinacine subfamily.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Organic Chemistry