https://doi.org/10.1351/goldbook.Q05012
Methylidenecyclohexadienones and dimethylidenecyclohexadienes, formally derived from @[email protected] by replacement of one or both of the quinone oxygens by methylidene groups. (The diradical, @[email protected] of quinodimethanes can also be called o- or p-xylylenes).
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