Accessing the decarboxylative allylation–divinylcyclopropane-cycloheptadiene rearrangement from the ketone/aldehyde substrate pool

Herein reported is access to allyl γ-butyrolactones and caprolactones that can undergo decarboxylative allylation/divinylcyclopropane–cycloheptadiene rearrangement. The overall sequence is brief (5 steps from commercial ketones/aldehydes) and yields diverse cycloheptadienes. The key decarboxylative allylation/divinylcyclopropane–cycloheptadiene rearrangement was unknown at the outset of our studies but recently reported by the Nemoto group. We disclose a complementary study to Nemoto's that further demonstrates the value of this transformation. Specifically, new routes to the key substrates are disclosed that ultimately results in improved scope of target cycloheptadienes.