Cyanoazulene-based Multistage Redox Systems Prepared from Vinylcyclopropanecarbonitrile and Cyclopentenone via Divinylcyclopropane-rearrangement Approach

A series of 4-cyanoazulene derivatives 1–5 were synthesized from 4-cyanohexahydroazulen-1-one, which was efficiently obtained by the annulation of the seven-membered ring on the cyclopentenone skel...