Synthesis of (+)-brefeldin-A

摘要: Two routes to (+)-brefeldin A have been investigated. In one the bicyclic ketone 2 was transformed into hydroxy lactone 7. Subsequent reduction, opening of heterocyclic ring and epimerization furnished aldehyde 13. Further steps towards natural product from this late stage intermediate 13 were not second route, readily available 17 converted enone 22. Conjugate addition requisite cuprate reagent afforded 3,4-disubstituted cyclopentanone 24 which brefeldin-A 29 in five steps.