Highly oxidized polycyclic natural products are abundant in nature and have diverse biological activities. Hyperforin has been identified as the sole constituent responsible for the antidepressant characteristic of St. John's wort. An approach to an oxidized bicyclic phloroglucin core of hyperforin is described. Puupehenone, a sesquiterpene found in marine sponges, has recently emerged as a strong candidate to treat tuberculosis. The synthesis of the BCD rings of puupehenone containing a quinone methide moiety is described.