biomimetic synthesis and structural revision of (+/-)-tridachiahydropyrone

Biomimetic Synthesis and StructuralRevision of (+/-)-

Tridachiahydropyrone

P. Sharma, N. Griffiths, J. E. Moses, Org. Lett. 2008, 10, 4025 – 4027

Present By Andrew Blemings

Dr. John E. Moses

• Master University of Bath, 2001, under Ian Rothwell

• PhD from University of Oxford, 2004, under Jack Baldwin

• Went to Scripps in 2004• Went to University of London

in 2005• Appointed Associate Professor

in 2007• Promoted to Reader of

Chemical Biology in 2011• 26 publications

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Tridachiahydropyrones

• First isolated in 1996 by Cimino from mollusks• Although synthesized by Jeffrey of Flinders in 2005, NMR did not

match natural product• Moses hoped to use Biomimetic chemistry to find the natural

product• Tridachiahydropyrones are used by mollusks to protect themselves

from UV light• Believed to occur via a 6π electrocyclization from UV light

– A thermal electrocyclization would produce the trans product– A light induced cyclization produces the cis product which

matches the natural product

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Woodward-Hoffman Rules

#e- Heat Light

4n Con Dis

4n+2 Dis Con

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Retrosynthesis

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Forward Synthesis

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• Ran last step in MeOH, hv, for 60hrs– Isolated the cis isomer in 29% yield

• Ran the last step again in xylene at 150°C– Yielded no product

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Questions

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