Experiments directed towards the synthesis of anthracyclinones. VI. Claisen rearrangements of 1,4-Bis(prop-2'-enyloxy)anthraquinone

Abstract

The Claisen rearrangement of 1,4-bis(prop-2'-enyloxy)anthraquinone (1) in N,N-diethylaniline and acetic anhydride has been examined. New products include compounds (3), and (6) and (14) in which a double bond has also migrated. Rearrangement of the compound (3) in o-dichlorobenzene affords the ketone (2), which supports an earlier mechanistic proposal.