The irradiation of 5-exo-bromo-6-endo-propargyloxy-7-oxanorbornan-2-ones in the presence of treithylamine leads directly to the formation of the eriolanin skeleton.
Synthesis of (±)-isoavenaciolide and of (±)-ethisolide from (±)-7-oxabicyclo[2.2.1]hept-5-en-2-one.
A short totalsynthesis of (±)-ethisolide and (±)-isoavenaciolide was accomplished from (±)-oxanorbornenone respectively in 11 and 12 steps, using a radicalcyclization as a keystep.